They don’t, but they define the socket the processor slots into and probably did this to market the newer chips as more advanced than they are (by bundling a minor chip upgrade with an additional chipset upgrade that may have more uplift).
I see no other reason to kneecap upgrades like this when upgrading entails the consumer buying more of your product.
I mean, fuck Elon and Tesla but if you’re spending money on a car you’re giving it to a bastard one way or another. The CEOs of Ford, BMW, et. al. might not be making asses of themselves on the global stage, but I’m sure they’re still horrible. Even used cars run on gas 99% of the time.