IMHO Krita is more of a drawing app (that’s what I use it for) and GIMP (I wish I could make a wish upon the monkey’s paw and get it renamed… To Libre Graphics Manipulation App. Or – LiGMA) is more for editing stuff
But yo’ure entitled to your own opinion ¯_(ツ)_/¯
The main draw of Mastodon for me (and why I didn’t stick with the *key servers) is following hashtags. Really eases post discovery in an algorithm free world.
Otherwise the misskey forks have all manner of neat features to make using them a delight.