TinyChan

Imagine you go to get your car's tires replaced but can only buy BMW brand (because that's what your car will support) and they cost 3x the price of the generic ones.
Imagine you want to do some home renovations but the builder of your house has installed a kill switch that will detonate the entire thing to the ground should you try to move even one brick without using their preferred contractor.
Imagine the manufacturer of your couch shows up to your doorstep 2 years after you bought it and says they need it back. But you paid full price for it? Nope, you actually bought a license, and the license has now expired. So will you get a refund? Lol, nope.
All of this would be laughable in the real world, yet when it comes to tech we look at the same practices and go "of course, all this makes sense".
So no, this isn't really about the "huge amount of work" it would entail. Companies are perfectly capable of doing this work, and happily do so as long as it benefits them. The problem is that there is no regulation in the space and customers have been trained to accept these practices as a way of life.