Coming back from Asia to certain parts of the US feels like I’m going back in time to a much poorer, undeveloped country.

No. It’s the network effect.

Because in order to make something like Airbnb, you need to get a lot of hosts and guests. Hosts won’t sign up unless there are guests and guests won’t sign up unless there are hosts.

These kinds of marketplaces are very difficult to get any traction.