The challenge with SC isn't so much what the engine is capable of. I know if all studios were just ask to make the craziest stuff possible they could get pretty serious and go well beyond what SC can do. It's the issue with building the tools and the content to fill out a game like that. And that's where the challenge is really going to sit on top of other things. Unless your game is purely sandbox, content creation is a massive issue for almost all studios. There is a reason why Bethseda games continue to look dated, and that's because their content creation tools are so massive, that they can only make relatively small changes to the engine without nuking over all their creation possibilities.
I like the idea that games could behave *like real sim models*, but only games that want to be like that (directionless), ie: EvE Online, SC, sandbox style games like Battle Royale, Mincraft etc, work like that. Everyone else has to spend a ton of time building curated content and storylines and suddenly all of those cools toys start getting tossed out the window because of game design and narrative logistics. They are trying to curate an experience for a player, as opposed to letting them discover their own. Once you get into curation, you start taking away a lot of awesomeness.
It is nice that the option exists; but I don't expect TLOU 3 to have players to be peering through portals and having their foot on each side each at the same time.