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?
IIRC Reddit closed their API to everyone they didn’t explicitly allowed to use it, meaning independent research isn’t easy.
Requesting paid access for research purposes would probably get you there though. After all, they need to sell access to posts and comments through some API to make money off all that data.