Per https://keybase.io/blog/keybase-joins-zoom, Keybase has been acqui-hired by Zoom.

My take is that Keybase is effectively a dead product, so what are viable replacements?

https://news.ycombinator.com/item?id=23103386 asks the same question.

So far, I've only found a couple of tools that do some of the things that Keybase did:

I'll update this as I discover additional tools.