To be fair, the likely reason in this case is AI companies mass-downloading Reddit posts for their training runs. You can’t really cache the internet, so from what I understand, every training run they scrape this stuff anew.

For many smaller sites, it’s effectively a denial-of-service attack, which is why lots of them have put up this thing:
Anubis bot protection screen

For Reddit, it might just be additional traffic that they have to pay for and which doesn’t give them any profit. Although, if Reddit is still as unstable as it was years ago, I also wouldn’t be surprised, if they got DoSed by that a few times as well.