I'd agree that it's hard to take an opinion seriously that pronounces Twitter as dead. As you pointed out, when OpenAI's drama was unfolding, the conversations happened mainly on Twitter. But saying Twitter's current form is the service at its best is also hard to take seriously. I tried to follow said conversation about OpenAI during Altman's ouster and I found the site to be an inconsistently broken mess. To this day, I'm still not sure why I'm able to access certain posts without signing in, but not others. In my experience, the quality of the discussion on the site as a whole has also taken a hit.
And again with the whole freedom of speech. It continues to baffle me how people associate Musk with the first amendment. He brands himself as a free speech absolutist, but his actions have continuously shown him to have no problem silencing critics and playing favorites on the platform.