Which is worse: a parent that clearly planned to have a child and never takes a personal interest in them, or one that clearly was an unplanned child and never takes a personal interest?

Both scenarios have a neglected child. Just one is planned and one is unplanned. So both are equally bad in my opinion because the effect on the child is more or less the same.

Would it effect you the same?
I think in the one instance, the neglect potentially has more impact. If a parent that was irresponsible initially, then continues a pattern, it carries a different meaning than one that shows more intent and includes an implied rejection from the neglect that follows.
- "Irresponsible initially" Geeze, crazy way to phrase it. What if the unwanted child was an accident despite precautions? And parents who didn't want the child could be expected to be not as involved (still wrong), but a planned child that is equally neglected means the parents were selfishly putting their own wants for a child above the responsibility of raising the child.
  There is no clean distinction between groups with the question you proposed, there are just too many variables that play into this sort of situation. Every family is going to be different, and every child going through this will react to the situation in a different way.
  "Which is worse, seeing milk your roommate sitting on a counter and letting it spoil, or forgetting to put your own milk in the fridge and letting it spoil?" What's the difference between them? Intention? Ignorance? Planning? How can you know from just those two examples?
- It's different but largely the same outcome. In one scenario the child knows they were never wanted and in another the child knows that they were wanted and then something changed causing them to be unwanted. In both cases, the child in question feels unloved and discarded. Which then leads to the child questioning their self worth and purpose in life.

I don't think attempting to quantify neglect to identify who is most traumatized is a healthy or productive exercise in this case. Both are bad for the children involved with so many internal and external variables affecting outcome.

It has deeper meaning to me, and I'm curious about outside perspectives to the point of playing devil's advocate if I must.
The next real conversational question is, what is the difference between a parent that is well intentioned but not smart enough to take a deeper interest in their child beyond just the child's fundamental needs, and one that is smart enough to have neglected to take an interest?
Edit: I'm getting the hint, I guess. People don't want the messy therapeutic hard conversations or deeper subjects.
Growing up, I went to a magnet high school. Every Wednesday, we would spend half a day in home room having discussions about topics like this. That was my favorite school experience; sitting in a circle of a mixed group and having an open minded discussion. The school was on the edge of some rough neighborhoods and was 90% black, k-12, admission by application only, uni prep, and on the campus of a state college. It was intended to uplift the best and brightest in the local community while drawing in students from a wider pool as well. This type of question is only negative if you choose to view it in that light. It is very healthy to be open to the potential perspectives and experiences of others even on hard subjects.
There is a lot of nuance in what can be neglect in this kind of question. The majority of neglect is likely ignorance and the result of continuing the mistakes of their parents. By discussing these things casually and openly, it increases community awareness and helps to potentially break the cycle by getting someone to think about how they spend their time and what it means to be a good parent.
- I find it impossible to have these kinds of conversations on Lemmy. Irl you can set up the structures to enable it - like ensure that everyone knows that it is a safe space to share opinions, none wrong or invalid so long as you approach it genuinely and don't bully others, etc. - but here...
  You'd have to create a niche community, and then nobody would ever hear of it, especially with only one post per slow unit of time.
  Plus typing is different than verbalizing, especially on a mobile.
  Plus people may want to avoid doxxing themselves by putting out so much personal info, which over the years can really add up.
  The structure of Lemmy is set up more for doomscrolling memes and occasionally firing off a retort, more's the pity.
  As for the question: it seems similar to this one, is it worse to be shot in the head or poisoned? For both questions, I don't think it matters: both options in them are bad, it being subjective which is worse, b/c beauty (and ugliness) is in the eye of the beholder, so it seems not a well-phrased question.

It doesn't matter as to the context, ANY form of child neglect is bad!

Hey I was a child of one of each!

You can't compare them. There's no scale of trauma, you can't say this was a level 6 while that's a level 8. They're both going to deeply effect you over the years in different ways.

Only way I dealt with it was by starting therapy.

My parents weren't great, but I think they did their best given their limited resources and the context of social norms at the time.
I too go to therapy. It doesn't help.

Worse for who? For the kid? Makes no difference. It's much worse for the 1st parent though. They are a super shitty person.

Both are equally irresponsible by definition. The only remaining factor would be if, in the first one, they tried to take an interest and failed, or if, in the second one, the parent knows of the child's existence.

At least the one who planned the child though would be caring for them properly while in the womb.

I didn't think of that one. That is a good point actually. It doesn't completely hold to reality with someone I know. I mean, she had proper healthcare and cared even though it was an unplanned kid.
I was planned, but parents have never really taken an interest in me, but they don't have many interests anyways, or friends for that matter. Their life revolves around cable TV and religion.
- Reminds me of a friend of mine. Was born as the second son to a birth mother who is disabled and would seem ill-equipped for many physical tasks but who wanted to live like Amy Schumer, as well as an abusive birth father who was often said to use her. He ended up severely abusing the friend in a way that almost left him dead and was sentenced to two months (because corrupt judge) and the birth mother was ordered to give the friend up but was allowed to keep his older half-brother and later gave birth to a younger half-sister. Not satisfied with this, after he was adopted, the birth mother tried pulling some strings to compensate for his loss while at the same time not revealing she was his birth mother or why he had to be given up for adoption, also trying to get his adoptive mother to play along, which is something she was also able to get the birth half-brother and birth half-sister to do. When the friend finally found out, the birth mother would constantly complain he wasn't interested in family matters having to do with the birth family or that he was making too big a deal about the abuse which she witnessed the effects unfold from which she publicly would deny the existence of, and things climaxed when the birth mother tried budding in and disapproving of his relationship, which led to an entire social dynamic ghosting her (except for the whole rest of the immediate adoptive family), but with her still trying to influence matters anyways, as she keeps doing. This is what I immediately think of anytime the topic comes up as I express that intent does matter.

First is worse

I mean I guess the first one slightly shittier but only marginally so. They're both pretty shitty.

Both are the same. You are what you put put into the world, the actual measurable effect of your existence, not the intentions in your heart that affect nothing.