That has more to do with boundary defence than the OS itself, and those are more-often-than-not closed. The majority of infrastructure that you are alluding to is also heavily locked-down.

Now you’re saying that—I as somebody that very much appreciates the advantages my…for instance…Apple Silicon MacBook Pro has over a ThinkPad running Ubuntu—should not have the right to purchase the product I like because of your ideology dictating arbitrary restrictions over what’s on the market.

Don’t conflate user freedom with just…being salty that not every product is for you.

That's baloney - virtually no computers these days are "cleanly separate" from their software, at least outside of tiny microcontrollers. Do you have any idea how much software executes before they even get to the point where the operating system beings to boot?

The idea that a CPU is going to come out of reset and start executing instructions that you provide at the reset vector is thirty years out of date.