Gb studio is a program and gb studio central is a website, did you get them mixed up here?

Its important to pay your artists.

Gb studio is not for making gba games many changes would be required for that to happen and is beyond the scope of gb studio. I personally think the ui is user friendly. You can build games for the gba using dev kit pro

Gb studio is free, open source and made by volunteers in their spare time, gba is a different beast. And if its so simple to add gba to it you are more than welcome to do it yourself 😊