Apple, Microsoft, Google - none is easy meaning you need to have Play store, certs, codesign, submit... But there are steps with few results making it easy for those platform to get the software.
I have tried my best getting also Linux but as the author said, there's nothing trivial (as my metronome GitHub issues can show https://github.com/talaviram/TICK/issues)
The name is exactly the tricky part... Linux has so many flavors. Even without installer, you have X server and Wayland and snap, AppImage, .deb each differ. add to that audio plug-in formats (CLAP, LV2, VST3) and the fact that some formats has no specific path for putting files.
For simple apps (not cli tools or ones aimed for package managers I start to think best is just providing an archive file (zip/tarball/etc)
While Linux is growing and is my goto for non-macOS, with so many releases, it still feels most users are more technical than other platforms. Add the LLM age where you can ask it to install it for you. a zip with binaries might be simplest for simple software.