> As far as I can tell they've pivoted to taking on Slack & friends with zero-knowledge team-chat, but global.

What? I'm pretty curious what gave you this impression, as I've always seen their chat app as an interesting use built on top of their encrypted file system work, but in no way their primary use-case or business.

We (and everyone else I know that uses Keybase) use it for passing around sensitive information, either through chat, their encrypted Git repos, encrypted messages plopped into emails, etc.

I think Fluidkeys is cool and all, but I definitely wouldn't switch off of Keybase for it, and I think you're doing yourself a disservice by pretending that Keybase is "just another chat app" now and not a direct competitor that also has secure communication built in.