Mojave Paint for macOS, edit images like it's 1999 - a Media & Video tool by jpsimons.
There's a million photo editors, there's a million design tools, and Mojave Paint can do those things in varying degrees but "graphical asset production" is its first and primary mission.
It's cheap! $9.99 (one-time, sad I even have to say that) for the "Pro" version. It's Mac-only, and Apple Silicon Mac at that. Does it look a little like Photoshop 5.5 from the year 1999? Maybe a little but also it's got plenty of its own original ideas. (Blog post on that is forthcoming…)
I've always been passionate about image editing tools for the technically-minded so I'm throwing my hat in the ring in that space. And sure GIMP is for the technically-minded but boy is it ugly on the Mac!