Git is hard because there are a thousand workflows to accomplish similar tasks. Github picked a few flows and rounded the edges and corners. This provided great value.
With gpg, there are already fewer workflows, and there aren't as many sharp edges as git, existing keyservers simply don't have rounded corners ;].
Isn't gpg already a convenient cli for basic gpg tasks? We have had public keystores (much like github) for decades. There are probably already links to some on your system.
Well, it isn't a PITA for me, and I couldn't imagine pointing my grandmother at keybase.io yet (but I could imagine installing a cert in her mail client for her). Maybe they have a sweet spot there and I am willing to accept I just don't yet understand who fits. But I don't think I'm that special, and I use gpg happily (and efficiently) every day.