Good luck getting that to ever happen in the United States. Also buses would be very impractical and near impossible to cover long distances.
Plus traffic.
As an edit: I’m not saying that busses are bad or impractical. They’re the best form of short range public transit. I’m saying that buses in the this scenario would be extremely impractical and logistically impossible to implement.
The people here have never driven through gridlocked rush hour traffic on the Manhattan or Brooklyn bridges, and think that a bus is going to magically make it to its destination without getting stuck for hours or chasing traffic jams on its own.