Because "they" will start to tell you when you can charge your car. And if you run out of range before your next permitted charge you can't drive.
The idea a car will plot your trip and plan your charge to keep topped off... nice theory. Is EVERY ev going to be wired together in a skynet setup, or, will you get 200 cars planning to charge all at one where there are 5 chargers not knowing everyone is headed there?
Really, it's disappointing where things are and where they've headed. It used to be people came here from behind the iron curtain and were amazed by the variety of goods you could get, how there weren't shortages, how you could start any business you want and make anything you want, same with buying.
Slowly, that has eroded to where special interests are trying to ban small motors, shelves are empty, inflation is rampant, and govt is force dictating changes to what you buy, own, use... even what you think/say has become a target where you're supposed to be woke or adopt certain ideology.. make no mistake about it, all these types of behavior inch closer and closer to soviet era type planned society.
That is part of the idea. There will be a planned shortage of chargers that will lead to rationing like during WW2. However, the rationing will also fail by design to lead into the elimination of private car ownership and you will have to subscribe to rideshare firms. If the technocrats get their way, it will be worse than thd soviets, they want a return to feudalism.