Gimp is a free solution, but unfortunately is very weak in terms of functionalities and interface compared to Photoshop.
I have been using Affinity Photo for a few years, and I have to say it is a very solid alternative to Photoshop. It only costs 50$ (pay once, no subscription, free updates ; also there is a promotion of 25$ currently). You get all the advanced features that photoshop can offer, like non destructive layers, smart inpainting, RAW development, smart brushes, export layers, and so on.
Affinity photo is compatible with their other softwares like Affinity Designer (alternative to Illustrator) and Affinity Publisher (alternative to InDesign).
I have been using Affinity Photo for a few years, and I have to say it is a very solid alternative to Photoshop. It only costs 50$ (pay once, no subscription, free updates ; also there is a promotion of 25$ currently). You get all the advanced features that photoshop can offer, like non destructive layers, smart inpainting, RAW development, smart brushes, export layers, and so on.
Affinity photo is compatible with their other softwares like Affinity Designer (alternative to Illustrator) and Affinity Publisher (alternative to InDesign).