I’ve dabbled with GIMP on and off for years but for simple image editing and touch-up I keep coming back to trusty old (very) Paint Shop Pro 9. I suppose I’ll give this new release another look. 
I have used GIMP for many years. If I were a professional photographer with a need to ecit many pictures per day - and if I was getting paid for the resulting images - Photoshop would be an expensive but no-brain choice. I could justify the monthly cost to use the industry standard flagship.
I am cash-poor time-rich. GIMP is clunky but powerful andcan be made to do much of what a top line editor needs to do. I am certainly taking v3.0 for a test drive
Hmm…there’s also krita.org, which looks more aligned with illustration, but can also do a bit of photo touch-up.
Ho Ho Ho!
PSing myself
That made me chuckle. As an aside I wear a sleep apnea mask which I call my gimp mask.
De riguer for the for the Big Meet?
I too have tried GMMP on occasion, if you are editing for screen viewing it is an alternative to Adobe options. Maybe I am unusual in that I still print images. I calibrate my monitors, my scanner and produce custom ICC profiles. I found in the case GIMP to be awkward to use. An alternative, still not as capable as Photoshop, is Affinity from Serif, single payment and occasional discount from ePhotozine make it an attractive option.
Had to make a small image with gif. Sorta did it in the end but was very difficult. It was the instructions of what I needed to do that was confusing though. Had to be an exact format to do it. Used it though and willl have another look one day.
I use photopea. Its a free browser based clone of photoshop. Compatible with photoshop files as almost idential. The best part is its browser based so no need to instal anything and can use it on any device.