I think part of the problem with a lot of "selling stuff on Linux" has been mucking around with different dependencies for the thousand different versions of Linux.
Historically, this has led to a couple solutions: either a) Just officially support one distro (usually Ubuntu), or b) just don't release a Linux version.
Flatpak has actually succeeded in making a system that kind of works everywhere, and I think it actually has a shot of being an equivalent to the Mac App Store.