In a few decades, electric toothbrushes will be so common that children won't know how to brush their teeth "manually"

Seeing as electric brushes have already been around for decades I doubt it will happen.

Also because electric brushes don't brush for you. You still use them the same way as a regular toothbrush, they just clean better.
- Wait... Are you people doing a "brushing" action back and forth with your electric toothbrushes?
  
  I just move it across each surface once in a slow kinda up and down zig zag — the way you would use an electric buffer or power washer to clean a long narrow surface with multiple sides... Upper set of teeth first; front, left side of mouth to right side of mouth. Repeat for top and back surfaces of teeth. Then repeat it all again for lower set of teeth.
  
  I guess the front of teeth could be combined into one surface, but I'm a raging psychopath.
I want like a USB c powered whole mouth toothbrush that looks like two u-shaped chainsaws full of tooth bristles that just wiggle back and forth very quickly and spray toothpaste and mouthwash as they go.

Where is that innovation?
- I've something like that but it requires brushing one half of your mouth at a time.
- Like a car wash for teeth

And so it is that you by reason of your tender regard for the writing that is your offspring have declared the very opposite of its true effect. If men learn this, it will implant forgetfulness in their souls. They will cease to exercise memory because they rely on that which is written, calling things to remembrance no longer from within themselves, but by means of external marks.

The thing that makes this seem unlikely to me is simply that a normal toothbrush is so much cheaper and doesn't do that much worse of a job.

My kids can't do a good job even with an electric toothbrush. My God! When do they learn to do it right?

We came up with a (quite stupid, but fun) "brushing teeth" song. It's to the tune of baby shark. It works out well and it takes almost exactly 2 minutes to sing. It also gets good coverage. My 4 year old daughter now demands it every time... 😬😅😬

Verses are:

Brush your teeth do do do do do...

Brush the top do do do do do...

Brush the bottom do do do do do...

Brush the left do do do do do...

Brush the right do do do do do...

Brush the back do do do do do...

Brush the front do do do do do...

Brush... Everywhere! do do do do do...

Now you're done! do do do do do...
- Lol nice. Awesome you were able to figure something like that out and it worked well. Good job!
I didn't learn well into my 20s when my teeth started falling apart.. it was less about learning and more about lazy I think.

Also, I didn't know until like a year ago that you're supposed to floss BEFORE brushing. That was embarrassing.
- I brush, floss, and brush again because I forgot to floss first. But I don't always floss. I don't think it's the end of the world unless you're having actual issues and need to adjust a bit to catch that variable.

Idk I've never tried or had the urge to try one. Possible, though.

I was always in camp manual, but my dentist adviced me a couple of years ago to switch to electric.

As I got older the wear and tear on my gums was showing. As you might know gums don't grow back or recover very well. I was putting more wear on my gums than necessary by manual brushing, even with me taking care not to brush too hard. An electric brush can get the job done without putting undue pressure or wear on my gums. It alerts me if I brush too hard, go too slow or too fast.

My dental health is excellent (for being an old man) and my dentist alerted me before it became a problem. Recently went for a checkup and he showed me how good my gums were looking, happy to have made the switch.
I've always used one as a child, but haven't had one since I moved out a few years ago. Now I bought one for myself a few days back. Idk what it is exactly but it does really feel like I'm giving myself a deep clean instead of smearing around the stuff on my teeth. Of course that's exaggerated, but if you're a bit lazy like me you should try one. I got mine on sale for 20 bucks, so its not like its super expensive.

I had electric toothbrush before, and honestly I don't see much benefits from it compared to regular tooth brush. Brush + floss is still the best way of taking care of my teeth

My teeth are definitely cleaned better by the electric brush.
Dentists can tell the difference. My buddy is one and told me he can immediately see that people that don’t use one have a lot more plaque.
i am extremely lazy and often dont brush as long as i should, e-brush makes it a bit easier and it has a timer so i know im not done yet. But overal for normal people i guess there isn't any real benefit
- Who says you're not normal? I can imagine many people are bad at tracking the time required for the desired cleaning result, or stick to wisdom they learned as kids, which might be outdated.
  
  That being said, your hunch about the effectiveness seems to be correct:
  
  https://pubmed.ncbi.nlm.nih.gov/24438077/
  
  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3459492/
  
  https://pubmed.ncbi.nlm.nih.gov/33225464/
  
  It seems children and people that need assistance whens brushing profit most from an electric toothbrush. My dentist recommended I use an ET, so I got an ultrasonic one, which resulted in a stark difference in how clean my mouth felt. It broke since then and I got a regular ET, but much like you, I love that the device tells me when I'm done or if I'm applying too much pressure, so personally, I can't imagine going back to manual.

My grandma told me how she used to cut branches off of trees and chew on them to turn them into bristles and then scrub her teeth with the bristles.

I have no fucking clue how to do that and I don't think anyone will ever hold it against me.

https://en.wikipedia.org/wiki/Teeth-cleaning_twig

We never knew. Fortunately electric tootbrushes saved us.

When I was a kid, we had regular visits at school from some kind of dentist group. They would show us how to properly brush and floss, and handed out free toothbrushes.
- One thing to note, if you find flossing very difficult, like you have to use a lot of force to put the floss in between your teeth to floss, your teeth may have spacing issues and you might need braces.
  
  I know this because as an adult I got braces and then all of a sudden I found it incredibly easy to floss. It's like 10 seconds and my breath smells better and my gums are healthier because it is easy and convenient to floss now.