There's a bunch of closed source ones, the best of which were brought by Adobe, but there's never really been a big open source effort.
GIMP say that the lack of separation between functionality and UI is why they're not behind an effort. That said they said they'd be happy to stick their name on an effort.
But this takes me back to my original question, why are there no open source photo editors, despite their popularity?
I tried and kept it, very good and basic FOSS photo editor with filters, stickers, text... This one is also good https://github.com/T8RIN/ImageToolbox
Oh my god finally found exactly the kinda thing I wanted with even more than I bargained for.
Yeah UI could use a tiny bit of polishing but it's still very fluid, damn.