I'm not in the loop here, most of the games I've installed from steam are in the 1GB to 20GB range, with a few outliers up to 80GB (I guess). IIRC some recent AAA games are in the 200GB range due to HQ textures. So I think 400GB games are realistic within the next decade. But honestly, it was just a random example. Just s/single 400GB game/400GB of whatever/ ;-)

Looking at the storage on my PS5, the largest game on it is the preload for "Horizon: Forbidden West" which goes live next Friday. It's 88GB. It's an open world RPG with several dozen hours of gameplay.

"Returnal", about a year older and a much shorter game, is the next largest at 60 GB.

Toward the bottom of the list are "Maneater" and "Life Is Strange: True Colors", both clocking in at about 15GB and as many hours of gameplay.

Having said that, your net connect isn't going to help with games. I have Starlink, which generally sits in the 150-250Mbit range. That should have taken about an hour to download 88GB. It took 7. The CDNs for game delivery aren't exactly speedy. (And that's pretty common, in my experience. Even in my last place when I had gigabit fiber, I generally left the console downloading overnight.)

No. Maybe 200. Usually less.

Latest COD is 140GB