GIMP is fine for the professional daily grind production/publication - acquire, crop, color grade, light curves, denoise, sharpen, optimize resolution, export, repeat... GIMP has the essential filters for these tasks, plus a little latitude for creative expression. In this regard GIMP is a totally valid competition for Photoshop.
GIMP loses as the use cases branch out to higher end improvisational artwork and fraudulent recomposition. It can use photoshop filters, but results are spotty. With capable AI locked behind vendor Paywalls, GIMP will never get those features built in, though plug-ins for those paid services are conceivable. However, feature limitations weren't what held GIMP back for me, at least not the only thing.
GIMP was historically an intrinsically LINUX X11 app, regardless of where was ported. Linux (and unix) feel weird in vague ragged cursor tracking, imprecise pointing/selecting, control click handling, open/save, print, import/export... It drove me nuts. Worse nuts than usual. Not in an amusing Deez Nuts way. Same goes for Inkscape (like Illustrator) and Scribus (like InDesign), which sprang from X11. I found them all frustrating AF to use, which made it feel like fail, even though the apps weren't technically bad. Even after years of practice, I got angry every time I had to use them. But ya can't do charitable publishing for moms, pops, schools, cops, clinics and 501c3 outfits at Adobe's prices.
Now I use Affinity Photo, Designer and Publisher for production work (so long as the printer/output bureau can handle color separation and trapping). The Affinity apps, now owned by Canva, are super nice at their price point (and hopefully remain so. Being native to the Mac OS, they are way friendlier than GIMP/Inkscape/Scribus. I still base my photo work in Lightroom, paying my monthly tithe until Affinity gets their catalog on. For Pete's sake, Canva, even GIMP has a plug in for Darktable.
The Affinity apps also lack some glaringly necessary features (Asset catalog database, bitmap autotrace, color separation with trapping, pre-press-ready PDF output), but maybe Canva will extend development (they made a big, bold commitment to price ceilings and feature advancement, which I still consider transparently B.S.). Admittedly, print production is all but extinct, so there's that.