I wonder why culs-de-sac don't ever follow a "superblock" model where everyone parks their cars in one place, then walks a short distance to their home? I under

I wonder why culs-de-sac don't ever follow a "superblock" model where everyone parks their cars in one place, then walks a short distance to their home? I understand that it's "less efficient" if all you care about is how fast you can get into and out of your car. But it seems far safer for children, far quieter for living, and cheaper because you don't have to build and maintain pavement roads that go everywhere.