Android apps on a big screen are not desktop apps [0]. Can you run desktop Firefox with all plugins there? Can you run native GNU/Linux applications in a terminal? Can you use the latest Linux kernel?
I have read it, and again I was already coding in the age of 8 and 16 bit computing, with their OSes built-in into ROM, no issues with them.
I also only cared for Linux because Microsoft wasn't serious about POSIX support back in the day and it was a solution for my problem to avoid commuting for an hour to access a DG/UX system.
If you computer places artificial restrictions on what you can do with it, then it's company participates in the war against the general-purpose computing.
If it's a technical limitation, it's a totally different thing.
I'm sorry that you do not care about the freedom of users. Users who do not know about all these things suffer from unlimited power of developers [0] and cannot do anything to escape various walled gardens and traps of proprietary systems [1].
Windowed Android apps running on full screen are desktop apps.
As for install any OS, then I guess Apple platforms aren't computers.