Darktable is great for “dark room” type things. I would put it into the category of non-destructive editing - yeah, you can crush shadows or whatever but the image is still pretty true to what the camera saw. Photoshop enables a lot more reality alteration. Remove/extend/edit backwards, touch up skin, change the color of clothing/objects, etc. I’m not a Linux user, and also am not aware of a great full featured alternative. For quick and dirty on windows, paint.net but that doesn’t help anyone on Linux :(