ST:Picard showed that Earth basically had a public transporter network around the world. It is how Picard goes from his vineyard in France to Starfleet headquarters. So, it isn’t all car flying cities.
However, if these are the people making decisions to deploy resources, why would they think of having ground vehicles at all? The only reason why the dune buggy was in Nemesis was because Patrick Stewart wanted it. Otherwise, it doesn’t really make sense.