Polygon count has generally been rising in games over the years. However, with the advent of mesh shaders allowing developers to use very high-quality models with billions of polygons (as seen in the UE5 demo breakdown) and very high-resolution textures with little to no performance penalty, game install sizes may seriously start outpacing SSD price to capacity.
Current generation titles like Red Dead Redemption 2 (150GB) and Call of Duty: Modern Warfare & Warzone (200GB) are already moving the needle. It will be very interesting to see what happens when developers start taking advantage of new engine capabilities.
I spotted a video testing mesh shaders (which could be levereaged to create an open world Sims). Data sizes were quite notable:
https://www.youtube.com/watch?v=1Bf_bnLlNT8