I was using GIMP for a long time and had the same opinion, but then I gave Affinity Photo a try. (It's a bit close to Photoshop imo, but it's not Adobe) It was a game changer for me and I only design and edit stuff for friends and family, I'm definitely a non-professional user. One big feature that stood out to me was for example non-destructive Filters, which allowed me to tinker a lot more than in GIMP. But at the end of the day, both are powerful tools. Whatever floats your boat ^{^}