Does it still charge as new?

Used cars still take a full fuel tank.

Yes, and it's easy to verify how much of the original capacity remains (95% typically).

The deprecation has very little to do with the cars themselves. It's mainly due to original prices being inflated during covid demand spike + chip shortage followed by releases of decent brand new EVs under £25K.

Used cars have piston ring wear that reduces their efficiency and thus milage.