I think Virtual Meetings (e.g. Zoom) are one thing, another, which is changing behavior at my company are Carbon Credits. We have published sustainability targets. Each department gets a certain amount of carbon, so in order to travel you have to be within the departments financial budget as well as the departments carbon budget... the latter is impacting the travel far more than the former. TATL and TPAC are MUCH more difficult to book than intercontinental / domestic trips because of the "cost".