I don't find Chat unsuable at all. My only team related emails are bug updates which are filtered. I feel group chats on Chat is a better UX than old Hangouts.
Edit: Disc: Googler.
Edit: Disc: Googler.
I think they've gone beyond making it unusable, I literally don't know how I'd find it if I wanted to, and they've long since convinced me that I shouldn't try.
FWIW, chat.google.com wasn't rolled out for @gmail.com accounts. It was being rolled out in Google Workspace/gSuite. And this announcement rolled it out to @gmail.com accounts. Old Hangouts is replaced by Chat for text and Meet for video. You can access it at chat.google.com.
Voice is for texting with your GVoice number. It used to be possible to integrate with Hangouts but it's not integrated with Chat. Chat just works with gmail/Workspace account and not a phone number. Voice works with a phone number.