If it was as cheap and easy to install a new engine as it is for an OS, I imagine swapping engines would be even more popular than new OSs. (And I think far fewer would clamor to replace their OS if it cost $x,xxx for each OS swap and took many hours of manual labor - I.e. I think whether someone wants something can be heavily influenced by whether it is ~free vs cost $x,xxx, etc.)

If it was easy, someone would’ve done something. with Darwin or many the other abandon/obsolete OS’s from the past…