I wouldn't put too much stock in these Reddit testimonials. I agree, there are definitely cases where individuals have used MDMA chronically, but I believe the percentage is much, much less than 1% of users.

There are also cases of individuals who believe they need to eat glass on a daily basis.

Anyone can convince themselves of anything if they want to believe it badly enough. I would be willing to bet that most of these chronic users would not exist in the first place had they sufficient knowledge about the drug.