I'd like the game to catch up with next gen. Xbox Series X runs on DX12 Ultimate. But the Sims 4 isn't Xbox Series X optimised yet.
When I play another game I notice the difference more in the graphics quality. I think it's getting better but it could still be a lot better. Maybe it will improve as Sims 4 is continuing.
I definitely find the game runs better on Xbox Series X though. But I put a lot of work in to make it run more smoothly by constantly checking my in game storage, inventories, townies, etc. I hoped I wouldn't need to do that on such a powerful console but it turns out I do.