The Ultra-HD Blu Ray PS5 discs can hold 100GB. FF7Remake2 comes on 2 discs. RIP digital owners. That sucker is taking up 200 GB on your PS5 while you play it. Or maybe it only comes on discs?
The SSD of the PS5 should allow them to load in the full world map. Or at least break it into 3 or 4 chunks and allow fast travel between them. They have the advantage of having mountains blocking the view of the world so programmers can use tricks to load it all in as you move around. Remember that on FFRemake1, the lead console was PS4 so there was no SSD to program and load around. So that's why you would get loading elevators and small crevice squeezing sections to load it all while you shimmy through a narrow crack.
I guess. Idk.
That's how studios cope with the development costs getting out of hand. Stylized art. Cel-shading. Sure, it's a couple generations behind like PS3.