I remember when Reddit announced it would begin charging commercial developers for access to its API, and in response, thousands of subreddits went dark in protest. I think it lasted for a couple of weeks. The CEO threatened the Reddit mods that he would replace them if they didn’t reopen the subs, so nearly every mod reopened and everything went back to normal. The CEO won easily without offering anything, and he was right when he said that ‘this too shall pass.’ Those third-party apps offered accessibility features for disabled people that Reddit still hasn’t implemented today. Now Reddit is getting even worse. How come there wasn’t a protest like that when they made even worse decisions?
Most of them stayed because they where already using the main reddit app so it wasn’t something that hurt them and didn’t care that much about the API, but with these updates it affects every user and made the experience worse for everyone.
Pure speculation on your part. I would claim the opposite and say most meaningful contributions to reddit came from PCs, not mobile phones. And those people preferred old.reddit.com to begin with.