Like I said, the 12V bus in an EV isn't driving a bunch of high power stuff.
Take a look at the fusebox in any modern car, EV or not. (There will most likely be more than one fusebox.)
You'll see lots of 20A, 30A, 40A parts, some even larger. Running those circuits on 12 volts takes more copper than you probably think it does. More copper and beefier (read: much more expensive) connectors. The move to 48V is frankly overdue.
Take a look at the fusebox in any modern car, EV or not. (There will most likely be more than one fusebox.)
You'll see lots of 20A, 30A, 40A parts, some even larger. Running those circuits on 12 volts takes more copper than you probably think it does. More copper and beefier (read: much more expensive) connectors. The move to 48V is frankly overdue.