It's a matter of power delivery at the moment. A modern rapid charger you can add about 10 miles a minute so 10 minutes is normally fine.. barely enough time to have a cup of tea.

Getting power to a battery faster starts to become impractical simply because of the thickness of cable you'd need to do it, and the internal heat the battery would generate if you threw power at it that fast.

Think of it like a swimming pool. You can fill it with a small hose, might take an hour or two.. bigger hose, maybe down to 30 minutes.. you want it to be done in seconds? Sure.. let me just turn up with this dump truck full of water...

Most of the things you read are about as useful as potato batteries. 'We've come up with this new compound that can take charge really fast'. Sure. Now make millions of them, the size of a car, for a price people will pay. Oh you can't... there's the rub.

Turns out there are a near infinite ways of combining materials that make a battery, and only a handful that scale to industrial production.