I don't see a single reason to invest myself into Google messaging product once again. I was adamant gtalk/hangout user but you can only fuck me over so many times.
To be fair, the migration from Talk to Hangouts was pretty smooth, and Hangouts still works. Google gave up pushing Hangouts for consumers but I don't think it's going anywhere, as it's a big part of G-suite for corporate customers. Though with Slack and Discord I'm sure it's usage isn't as strong as it once was.
Hated hangouts, finally switched to Telegram and will never look back.