Because consumers have been conditioned to expect that extended warranties are just another layer of scam, maybe to extract consumer data, maybe just to get a slightly higher price. I think if you see these then you have to assume they are unenforceable anyway due to some fine print, and you risk finding this out after spending way too much time navigating terrible robot phone systems and similar harassment.

In a lot of contexts, consumers will never be able to trust products/manufacturers again. What can work though is if stores/distributors provide the warranty though, because unlike consumers, they may still have some power.