Stating that you eat as much as you want is meaningless. How many kcal/day is that exactly? Most people are terrible at estimating their calorie intake.
People putting it down to eating less are parroting the food equivalent of abstinence-based sex education, and we’ve been drumming on that for like the last 30 years. We have to find what’s making people want to eat to excess, not just tell people to eat less and exercise more. That obviously doesn’t work.
If you think that there's something else going on, then let's see some hard data.
Personally, my "satiated" level is very low. When trying to gain weight while weightlifting, it was difficult to eat the amount of calories needed. I know others who can easily eat twice as much as me in a sitting and not feel full. Something different in happening in our bodies to signal "stop".
Eating less and exercising more does work. Talk to dedicated lifters about their cutting/bulking, where they want to be, and talk to them about it again in six months if you want to see how effective it is. It doesn't work for a lot of people because in the short, medium, and arguably even long term, it doesn't make you feel good.
There are a handful of people that can struggle to gain or lose weight on a diet appropriate for the amount of exercise they do. You may be one of them. If you are one of those people, asking why other people struggle with it is like being a 6'6" basketball player and wondering why somebody who is 5'9" struggles to dunk like you can.
There is a massive difference between being at a calorie deficit and starving yourself. I don't even know what to say -- this horse has been beaten to death by countless thousands of people and it's wild that anecdotal evidence with a sample size of you is enough to justify theorizing an alternative to an incredibly simple idea that until a few generations ago, there was absolutely no evolutionary pressure to not want to eat everything you can.
I suppose you'd say that some areas experienced more evolutionary pressure to eat as much as possible than others due to differences in food security?
But being hungry/unsatiated is distracting and can decrease your performance on every other task you do, so I don't really agree that there's no counterpressure. And I doubt that people in even those less food secure regions are just hungry all the time, like some obese people here describe being. It really seems like something just gets messed up in the signalling, which makes it seem more like a health problem/malfunction than some built-in evolutionary drive that doesn't fit the modern world.