GIMP is definitely not a daemon; I don't think it even has a run in the background mode. Maybe something with snaps?

Gimp is not typically used as background process. It's primary use is as an interactive tool with a UI, therefore it's not typically a daemon. [1]

[1] - https://en.wikipedia.org/wiki/Daemon_(computing)

It's not the greatest, for sure, but it's a complex tool for a complex task.

If you think Gimp is terrible you'll hate something like DaVinci Resolve.