But it doesn't take many later versions of Photoshop to start becoming more productive than using GIMP because of functionality it has that GIMP does not:
Adjustment layers were introduced in 4.0 (1996, GIMP didn't even exist yet)
Layer styles were introduced in 6.0 (2000)
Smart Filters were introduced in CS3 (2007)
They're all invaluable tools that provide a non-destructive workflow where you can go and edit a change you made without having to undo everything you did after that change and redoing things again.
If I had to use an ancient version of a program and have nothing but that program until the end of times, I would pick Photoshop CS3.
This entire class of functionality still does not exist in GIMP.
A lot of modern tools can be added to GIMP through the G'MIC plugins (like the healing tool), but the core editing loop functionality, what is in my opinion the most important thing, is extremely primitive and outdated. All of the competition provides non destructive editing. Including other open source software like Krita (which focuses more on painting tools rather than photo editing, leaving a hole in the open source ecosystem).
But it doesn't take many later versions of Photoshop to start becoming more productive than using GIMP because of functionality it has that GIMP does not:
Adjustment layers were introduced in 4.0 (1996, GIMP didn't even exist yet)
Layer styles were introduced in 6.0 (2000)
Smart Filters were introduced in CS3 (2007)
They're all invaluable tools that provide a non-destructive workflow where you can go and edit a change you made without having to undo everything you did after that change and redoing things again.
If I had to use an ancient version of a program and have nothing but that program until the end of times, I would pick Photoshop CS3.
This entire class of functionality still does not exist in GIMP.
A lot of modern tools can be added to GIMP through the G'MIC plugins (like the healing tool), but the core editing loop functionality, what is in my opinion the most important thing, is extremely primitive and outdated. All of the competition provides non destructive editing. Including other open source software like Krita (which focuses more on painting tools rather than photo editing, leaving a hole in the open source ecosystem).