Aluminium is actually a better conductor than copper when you judge it by mass, not volume. I think also by tensile strength.

In any case there’s a reason that large overland wires aren’t copper, but steel-cladded aluminium. Copper will always have its applications but so does gold and yet we’re not running out of gold to plate connections with.

In cases like windings requiring more volume is actually an issue, in the case of PCBs… no, despite Apple’s insistence, it’s actually fine to have a phone that’s 0.2mm thicker.