It's sad to say but Photoshop smokes basically all of its competitors except the ones that get into a specificic niche, but even then stuff like illustrator and lightroom compete well in that marketplace.
Photoshop may not be FOSS but it may as well be considered free due to the rampant piracy. I frequently recommend it forgetting it's a subscription based Ad*be made product.
Serif's Affinity suite isn't free, but the UI is much more approachable than GIMP's. The maintainers also aren't being weirdly defensive about a name that's a pun of a slur or sex thing.
Pretty steep, it's software aimed at professionals, and it shows. There are a few tutorials from Black Magic design where you can download the source media and follow along, which I found very useful.
I found you really need to spend a few evenings learning the software before you actually edit anything.
At this point, I'd say it's not just correct but a moral obligation. Adobe has caused incalculable damage to the softwarescape by buying up smaller but popular companies, shoving their products full of AI crap, and putting them behind a subscription.
Allegorithmic used to have Linux releases for several of their Substance products. They no longer exist. Guess what fucking happened.
Technically Substance products work too on Wine, but with a massive hit to performance because they use the GPU through some esoteric API that isn't covered by DXVK or VKD3D.
I’d like to interject for a moment. What you are referring to as Linux is in fact GNU/Linux or as recently i have taken to calling - GNU+Linux. Linux is not an operating system unto itself but rather another free component of a full functioning GNU system made useful by the GNU corelibs, shell utilities and vital system components comprising a full OS as defined by POSIX.
So cgpeers has been the best place to get those from for me buuut they closed registrations a couple of years ago now. I can throw a link to the 2024 monkrus version I grabbed though. Not sure how people are with straight up linking things in here though.
I feel like it's even advantageous to them to pirate. If everyone wanting to work in graphic design pirates Photoshop, they'll know how to use it in the business world, and their work will buy it because it's what everyone knows.