Because of zoning laws in a lot of places that’s not possible.

For instance, where I live, restaurants are restricted to commercial zones. Housing is restricted to residential zones.

That also gets into the question of “why” do we have zoning laws, and that gets complicated, because it was most beneficial in separating factories and utilities, and very noisy and polluty things from where people lived.

Unfortunately they also had the idea that any enterprise fell into this idea, and the other businesses didn’t want to mix with other polluters and residents and it became a big mess