I feel like the limit of what these motors can do now is being held back by something they can't control anymore, tire grip.

I think a lot of these software updates on the acceleration speed aren't because they all of the sudden figured out how to get more power from the electric motor. I think it's from tweaking the "no-slip" system or whatever they call theirs. Basically when the car detects it's losing grip, it cuts back the power. I think this is a balancing act on how to get the system to push the limits of slipping without putting the average user into a ditch because they tried out the "ludicrous" mode.

I'm sure on static conditions in a lab, Tesla can make the thing do something like 2s. It would require something other than a regular tire on a regular road though.