Twitter definitely jumped the shark a while ago. The hashtags got hijacked by brands and activists for hollow signaling and marketing. Retweeting and quoting got repurposed to shame and bully. Forced brevity got redirected into hot takes and memes. It was the core community who did it all first.
I suspect Twitter has been pushed aside by many for more private and granular services like Discord and Slack. Discovery there is a problem though, a million chat rooms of 10 people each make for a poor community. In some ways it's like the living rooms of Iran: most know public discourse is messed up and broken beyond repair, so they only speak openly behind closed doors.
If Twitter could admit that and shift gears, there might still be some hope and a future in it. As it stands, all they're doing is giving people better shovels to dig themselves deeper into the hole of their own making.