Adobe compatibility
GIMP and Krita support .psd files and it looks like Inkscape does with a plugin.
They can have very basic compatability but for things like adjustment layers and smart objects nothing that isn’t Photoshop will work very well. They also lack raw processing. Every open source raw editor I’ve tried is barely usable as well (though there is other proprietary software which is comparable to Adobe on that front).
Even affinity wouldn’t be possible for me to use because everyone I need to give and receive files from would need Adobe files, and the possibility for something, even a little detail to not work because of a comparability issue would be a deal breaker and major pain in the ass.
