I've never seen or hear anyone I know use Keybase.io for actual texting, and I work at a large software company. Everyone just uses it for PGP keys, then forgets it exists.
I was one of the early adopters (July 2014) and I used it for texting for a time.
When they started pushing cryptocurrency I felt it was time to leave, a short time after
Zoom bought them out and I was glad that my account was already purged.