Agree about the learning curve, and also… it’s really no different than diving into PS – which costs an arm and a leg and is subscription based.
There are a ton more of these free photo/image manipulation, and photography and even video related softwares. Many of them curated at https://pixls.us/
Another one that I recommend that is a sweet replacement for Adobe’s “Lightroom” is “Darktable”.
For artists looking to make vector work – stickers, t-shirts, band/concert posters and the like, a couple of highly recommended softwares are Krita, and Inkscape.
