Unfortunately 99.998% of the population can't do that. I'm glad you found a solution for yourself, but that doesn't help everyone else, so everyone else will reward the manufacturers by buying them and leaving them able to phone home, so manufacturers will just push the boundaries a little further next time and that might impact you in a way you can't easily mitigate.

Obviously, but I also vote for right to repair laws and "reward" the right manufacturers by telling my family to buy devices that are easier to hack/repair.