Keybase is not end to end encrypted and can't be compared to Riot or Signal.
Keybase claims that it is, but it's a lie that nobody verified: https://security.stackexchange.com/questions/222055/how-can-...
Keybase claims that it is, but it's a lie that nobody verified: https://security.stackexchange.com/questions/222055/how-can-...
Hopefully none of that changes now that they've been acquired by zoom.