It’s definitely a black mark on Xbox that they couldn’t get splitscreen on Series S; but it does seem like that specific feature needs a lot in the way of CPU power. Hopefully that doesn’t spell trouble for future releases like GTAVI.
I've played through with a switch controller. It's good, only downside is when you need something specific in your inventory, typing to search isn't there, which comes in handy when you need to insert specific quest items. But like I said I played it through, very usable.