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affinity.serif.com
very similar workflow to photoshop, fairly comparable feature wise, getting quite popular in the DTP crowd. And best of all it's one fee of 50 bucks, unlike photoshop for which you get charged monthly.
Japanese cartoonists and illustrators are using openCanvas!openCanvas is a paint/drawing software program from Japan, it is used worldwide and received many software awards.
www.portalgraphics.net
again very similar workflow, quite fast but more geared towards digital painting than photography. Costs 60, bu when on sale you can get it for as little as 25.
if you're interested in retro pixel graphics:
Asperite https://www.aseprite.org/ 20bucks
nothing like photoshop, it is more like a spiritual successor to deluxe paint IV.