if that was the law how would you enforce it in any meaningful way?

Through the OEM. Wouldn’t be hard to create a system that tracks location locally using GPS and electronically applies an according speed limit from a govt database

Acceleration is a simple matter of distance/time/time.

Mechanically minded people mod cars everyday.

People break all sorts of laws every day. It doesn’t mean you don’t bother making them.

Then police would have more reason to F with everyone at their pleasure.

Actually they’d have less, considering cars would be physically incapable of speeding.

You would for sure need more surveillance from the state. Probably need more expensive proprietary anti-consumer tech inside the car you own.

…for what?