Affinity - Paid, Closed source, no Linux version Paint.NET - Closed source, Windows only Photoscape - Closed source, no Linux version Canva - Closed source, sub

Affinity - Paid, Closed source, no Linux version Paint.NET - Closed source, Windows only Photoscape - Closed source, no Linux version Canva - Closed source, subscription webapp None of these fill the niche GIMP has claimed and I just feel in whatever alternate reality where the creators of GIMP never made it that someone else would have made an app that would manage to ship adjustment layers within a decade.