I'm sure for anyone who has real work to do, GIMP will hold them back compared to Photoshop.
But I grew up using GIMP and got some pretty impressive results with it. Now that I have Adobe CC access and have been using Photoshop through that, I am perpetually confused on how to do x, which I know how to do in a couple clicks in GIMP.
To be fair, I'm sure that'd go doubly so for someone who started with Photoshop since it does have an objectively cleaner UI.
Ah, the good 'ol Heard Turd