Or the site being infested with bots and generally getting slowly shittier?
Bluesky is small and lame.
Mastodon/Lemmy are fragmented fiefdoms.
X/Twitter is full of dark patterns, bots, and invasive of privacy.
Basically everything sucks.
But those aren’t the biggest things that killed it. The biggest thing was losing the attention war to doom scrolling. That’s where everyone is now, at least online. They are scrolling.
TikTok, YouTube (esp shorts but increasingly all of it), Instagram, and so on.