I suspect these changes come from very different motivations. My guesses —

Reddit's changes are a desperate attempt to please investors. This is a standard tactic for tech startups that are having trouble showing a profit: figure out what the company has been giving out for free, and start charging for it. They looked at API traffic and said "what do we have to do to monetize this?" and the current situation followed directly from that.

This is not just a vague appeal to "the market"; there are specific big-money investors involved, and they will have been communicating directly with Reddit management on what they want to see from the platform. CEO Huffman is probably listening to specific advice (or demands!) from those investors, and making policy changes to appeal to them.

Twitter's situation is quite different. The goal of Musk's takeover was political: to reverse Twitter's user conduct policies, which had led to Donald Trump and other fascists being banned from the platform for shitty behavior.

Twitter is falling apart on a technological level right now because most of its skilled engineers have quit, leaving the company no longer capable of responding effectively to technical problems.

It's clear that something is going on. At least for Reddit and Twitter, they need to make money. They've made that pretty obvious but it is curious why now. Facebook and others didn't seem to have this issue. YouTube sounds like google just Google

I'm not sure how Lemmy will last if it grows massively. But I'm here for a good time not a long

Don’t forget YouTube disabling the video player all together if they catch you using an adblocked

Lemmings!

Let's please not start the "redditor" like bullshit here, thanks.