I don't think twitter has anything to do with reddit -they don't exist in the same niche in social media. The sputter of mastadon was because the decline of twitter was largely short term outrage. I hear every day on hackernews that twitter is failing and I'm not sure that's true.

Twitter and reddit exist because there is a market for those types of social media experience. If even 50k computer science specialized people stop visiting reddit and twitter I don't think that matters to those sites overall traffic levels.

If you already aren't visiting twitter or reddit than you aren't really interested in the alternative for them, are you? Since you're already rejecting those experiences. You aren't the target audience, you're just imagining everyone is like you, when all evidence seems to go the other way.

So again, lets say people want an alternative platform to twitter, they could go to substack maybe. but whats the alternative to reddit? Discord? I don't think so.

Can someone provide a tl;dr that specifically explains why this is going to harm the site? I know there were some communications problems with third party clients, but from my reading of the announcement it just sounds like they're going to start enforcing their previously documented but unenforced API rate limits on free accounts and they're providing a service to charge for bulk access. What else is changing that has everyone upset? The developers commenting from the big clients such as Apollo didn't seem to provide any info on if/how their clients would be broken. I didn't even see any comments suggesting the clients would break. It's mostly just anger about the opacity of the announcement.

I understand people being wary, especially in light of how Twitter changed their API years ago, but I'd love some more concrete info and specific complaints about this change in particular.

but lets say they're upset enough to leave - where will they go en masse that replaces reddit?

Gotcha, thanks