I used to use Paint.Net and lack of it on Linux was one of the things that kept me on Windows. Now, though, there is a passable clone of Paint.Net on Linux; it's called Pinta. Apparently it's available on Windows, Mac and even BSD now.
I had that installed for a while. Didn't much care for it. jspaint though, is an exact clone of the XP era windows variant. It works right in your browser on any computer. Even chromebooks! There's also .exc and .deb versions for windows and linux you can install and use offline. Installed on my setup without a hitch. Now if only I could get Linux to run Star Office 5.1...
Really surprised me it wouldn't run correctly, since it's an early Linux derivative. Like trying to run old windows 98 software on windows 11 I suppose. I had high hopes for LibreOffice, a successor of StarOffice, but one of the components of SO, StarImage was left out. Otherwise it's near identical. I've yet to find an alternative as good or as simple to use.