I am also curious here. I have used and advocated strongly for Keybase with a couple of local government clients to send sensitive files back and forth (not sensitive in the sense of national security, but more to preserve privacy and store encrypted at rest).
But I want to get ahead of the concern that Keybase is now owned by a Chinese company, which instantly compromises it.
PGP is dead on arrival, since it's an overcomplicated mess.
Keybase felt like WireGuard for its use case, just dead simple and also secure.
Update: I just want to clarify that I am happy for the Keybase team. This is clearly an Aquihire meant to bolster Zoom's security talent. And as a Zoom user, I'm generally happy about this development. But there will definitely be a concern about them being acquired by a Chinese company.
Update #2: I thought about FooBarWidget and others' comments, and I'm going to alter my wording. Zoom isn't a Chinese company, but their development team has been entirely based in China all this time and there have been concerns about that (which are entirely legitimate for certain groups like governments, in my opinion), especially given their communications aren't e2e encrypted.