There’s nothing quite like Photoshop, but Photopea helps bridge that gap. Soon™ Gimp 3.0 will be out which will help too. Depending on your needs, Krita is very high quality and up there with professional paint applications. Then there’s a bunch of other tools that fill in more specialized needs here and there. It’s more so a matter of combining & linking the alternatives together to cover your needs best you can than relying on one end all be all application.