Basically you can get much better read performance if you can read everything sequentially and you want to avoid random access at all costs. So you can basically "hydrate" the loading patterns for each state, storing the bytes in order as they're loaded from the game. The only point it makes things slower is once, on download/install.

Of course the whole excercise is pointless if the game is installed to an HDD only because of its bigger size and would otherwise be on an nvme ssd... And with still affordable 2TB nvme drives it doesn't make as much sense anymore.