Not saying that the person in the post is correct in conflating those words, I don't think that's accurate at all.
However, it is disheartening to see so many ill-informed comments about fatness here... It's way, way more complicated than just "calories in/calories out". Even the extent to which it's unhealthy is more complicated; obesity is linked to higher risk of heart disease, but also linked to higher probability of surviving strokes/etc. A lot of the problem stems from the fact that BMI is a nearly useless metric.
Human beings are subject to the laws of physics. If you eat more calories than you consume and do not otherwise eliminate from the body, they will still be in the body. The body stores them as fat. This is simply the mechanics of biology. If it weren't, things like Ozempic would not spur massive weight loss.
We have more obese people now than have ever existed. Countries that do not have US/Mexico levels of easy access to heavily processed, calorie-dense foods do not have obesity problems like we have. Clearly, calling people names and making them feel bad is not a good way to get them to adopt healthier habits. However, there are plain, uncomplicated things that people can do to lose weight that will work, but they will ONLY work if the people want to change, are honest with themselves and truly stick to the changes they need to make.
Losing weight is absolutely within reach of 99% of obese people, but comments like this reinforce the absolutely incorrect notion that getting healthy is some big mystery that's for a different class of people to solve. It's defeatist and makes it seem like a problem that a person can't solve on their own, which is straight up wrong.
The plain, uncomplicated things you can do? Find out how many calories a body of the weight you want to weigh uses in a day. Limit yourself to those calories. Given time, you will be that weight if and only if you stick to the plan. It may shock some people how many calories they actually consume in a day, especially if they drink soda or juice with any regularity.