The irony is, if your mother bought a reasonable new fridge, it would probably pay for itself in five years.Dollars to donuts, they don't see it that way. They're all the same so if you don't buy X are you going to buy Y if X and Y are the same? Firmware updates are great for what is in the box today. Firmware updates won't necessarily fix something that they don't even know exists, if that makes sense. For example, can you get HDMI 2.1 support from an update? (PS: Literally asking because I don't have a clue! That's a lie, since if I could, I would). As another example, on my Samsung, there was something called "Evolution Kit" which was some type of future proof for the TV. After the marketing hype, I never heard anything or used the evolution kit. Samsung never contacted me to say hey, let's update your evolution kit... Utter nonsense, it turns out.
I guess the moral is, if you're happy with what you have, enjoy it until the leds starting falling out of the back of the TV. If not, there's a wide array of new and better stuff always available.
My mom still has a freezer and a fridge they bought when they moved into our home in 1968. They just replaced the boiler a 4-5 years back. They probably have negative efficiency ratings, don't cool or freeze as good as modern units would but my mother has never said I need a new freezer, or whatever. Only after a bathroom flooding destroyed her kitchen did she replace the original stove and cabinets, btw, in the house since it was built. Different generation. Different needs.