Nobody installs apps on their microwave, router, home appliances, etc, at all - certainly not in a way approved by the manufacturer.
Cable boxes are rented, not owned, by consumers. If a consumer stops paying at any point, the cable company requests it back and bricks it. This is not like any other device listed in the conversation.
I meant to exclude game consoles from the conversation when I used the word “major”, but as far as I’m aware, every single game console permits software to come from physical media, which can come from any retailer. I’m not forced to buy games for my Switch exclusively from Nintendo - I’m free to go to Walmart, Best Buy, Game Stop, Target, Amazon, etc to go buy games for it.