Why are there so many players who have really low elo and play for years

I just need to figure this out. Chess.com has soooo many players with elo below 700 who are playing for long years. It would be easier to understand reasons if they didn’t play that often (4k games, I even saw 11k). I am not better than them, but also don't play that often. The thing is that they play in such a strange way: they do rarely make blunders, but also sometimes don't notice obviously great moves, but good in defence. I cannot precisely describe them... Why are they so bad and stagnating in rating? If they play that much, what prevents them from improving? Maybe watching tutorials or reading chess books? Isn’t it more fun to play higher elo?? Are they insane?

in lower elo I cant progress bcc of weird openings

Not everyone equates fun with increasing rating. Many people play chess simply because it is enjoyable, at any level.

Maybe at the beginning they want to improve like everyone else, but at a certain point, realizing that they can't go much further (for some reason), they no longer think about their progress and simply enjoy the game.

In the club I frequented a long time ago, I met many players who went there every evening, had always played the same way for decades, as amateurs, had no interest in improving, and happily spent that time. They weren't insane at all.