I repeat, based on the extremely large numbers of vault downloads of stadiums, yes, a significant improvement in SC that would allow the relatively few honest stadium designers who exist to create more realistic historic, modern and future stadiums, would impact the game more than any other single addition or update. Again, the stadiums are the biggest part of the game's play background. It ranks right up with other basics like player animations, ball, pitch, and hitting physics, and basic game play engineering.
No other single mode of this game has such a tremendous impact on the vault. Stadiums exceed the vault use for logos by a huge amount. That's despite the current reality that the stadiums one can create in SC are quite limited in their options. Those are not opinion statements but verified by the numbers.
I firmly believe that if SC would allow designers the legitimate options to amend the backstop, baseline, and outfield walls in ways that allow replication of any stadium from the turn of the 19th century to modern day, and we get the sought after changes in how props interact with each other as well as the walls, and we can then replicate same.
You start seeing very faithful stadiums from historic eras and that alone will increase game appeal. If the DD community would stop demanding that SDS rein in stadiums that are considered "cheating options" or simply agree that no custom stadiums be used in online competition modes, then the rules barring our creative options would be removed. That would unleash a creative avenue that over short time would introduce a wow factor with the stadiums this designer community could create.