They didn't say "expect it not to work", they said "expect it not to work for you". As in, it's working for the manufacturer/software owner, with their interests in mind first and foremost. And it is likely to eventually start doing things that make your life worse and their lives (and bottom line) better, because only they have control over it and why wouldn't they start to extract more value at your expense if they can?
Laptops still let you install what you want. Android tablets and phones (now with a bunch of ugly, concerning hoops) still let you install what you want. Hell, even Steam decks let you install what you want, up to the point of replacing the operating system! Lots of consumer electronics let you install what you want and therefore work for you. To claim otherwise is to be defeatist.
And further, plenty of things either don't have a screen (including refrigerators) or, in the case of TVs, can have their internet connections disabled and be connected to other devices which you do control. Don't give up and assume you have to cede the right to every surface in your home to companies trying to extract more value from your life!