It's also good for security; the legislature won't need to get shut down if there's a private plane deviating from its flight plan in the area. Even if lobbyists do manage to meet in person without monitoring, their travel costs (in both money and time) would increase, while the cost of maintaining the representatives drops.

This plan also has the benefit that it can be phased in gradually. Start by plumbing the district offices for videoconferencing, then install the equipment, then start holding sessions that way. Over time, sessions can shift more and more to videoconferencing, and the building in DC would gradually be used only for ceremonial purposes.