Troop transports are kind of a red herring here. The issue isn’t moving troops, it’s moving their equipment. You can pretty easily move a division’s worth of troops by air (activate CRAF and requisition a few dozen 777s, boom, done), but it’s a lot harder to move their equipment (tanks, helicopters, artillery, air defense, ammo, etc.) that way. If the troops don’t have pre-positioned equipment in the battle area, then it really needs to get there aboard ships.

I’m of two minds about re-creating the logical and industrial capabilities of World War II (or, at least the subset of them needed to fight a major conflict with a near peer). On the one hand, I’m pretty sure that enough money could and would be thrown at the problem to solve it. On the other hand, I’m not sure any direct confrontation with a near-peer military would last long enough for that to matter.