GPG - without trying to devalue the good work put into it - is also one of the tools with one of the worst command line interfaces I know; by default it prints a confusing amount of wholly irrelevant, debug level information, to the point where it's hard to see where the actual output is (eg. --verify success). A slew of different key identificators (short ID, long ID, fpr, name, email, ...) that are all mixed in a bunch of places and only sometimes interchangeable etc. etc.

The UX is just horrendous, and none of the GUI tools improve on that.