The faster the charger, the more powerful of a charging station you need, and the more expensive they are. No matter how fast your car is capable of charging, it'll be limited by the charging station so the speed itself won't change.

On the other hand, solid state batteries are supposed to have quite the increase in charge density so there's the hope that they can be a lot cheaper since you don't need as big of a battery.

On the other other hand, isn't the car market slowing down as a whole? Sales seems to have slowed dramatically these last few years as people are relying on other ways to get around more and more, so rather than replacing cars with EVs, it's more like cars are just plain disappearing, even it's only at the rate of partial replacement levels.

probably not enough to match the demand if everybody switched to electric cars overnight.

The same way that McDonalds wouldn't be able to cope if the Public suddenly discovered Mig Mac Sauce can prevent cancer?

It's okay to plan capacity a little less aggressively and then come up with demand, and not coping with a bizarre surge is almost okay.