They'll lock it down like an iPhone soon enough. The writing has been on the wall for years. Apple and Microsoft are frothing at the mouth to do this. But they have to do slowly boil the frog, because they know it's the only way people will accept these kind of changes.
People have been saying this for more than a decade, but it still hasn’t happened; there are still zero restrictions about what you can and can’t install on macOS.