xkcd

A counterpoint to that is things like batteries, ram, motherboards, etc. in laptops (and pretty much every other device that uses rechargeable batteries). The fact is that for better designs the batteries are probably not going to be easily standardized in electric cars (also kills innovation).

PC motherboards aren't trying to use the least amount of space possible, because desktops can be large. The same isn't true with cars, the space matters.