Krita has been adding photo manipulation tools faster than GIMP is fixing their UX/UI, so at this point I think Krita will be the first to become the most viable FOSS alternative to Photoshop.
devs have to eat too, open source software (when fully free) is sometimes built as a hobby like Jellyfin, or as a portfolio project, or worst case scenario as a bait and switch to paid (sometimes it’s death sentence). Then there are sponsored projects like Vulkan, or others that live off of donations like Mozilla.