This is not correct. Look at what is happening in the Amiga retrocomputing area. Some of them have Linux support along with AmigaOS/Morphos and Aros. Pretty succesful (expensive though) because they do not release 1000 different systems each year but 2-3.

Also, you do not have to support every system.

For example if they support these cheap n150 mini pcs, I am more than fine. Something common.

Macos runs fine because it works in a specific space.