That's a short term dip. People may be able to stop flying for a few weeks or months. but, all those businesses will still need people to move around the globe. then again, maybe this will prove to the world how unnecessary all those flights were to begin with.
According to some figures I found with an extremely cursory search, leisure flights account for over half of air travel. So even before we start asking how many business meetings and conferences really require physical presence, there's a vast amount of personal air travel that is largely optional.
If this pandemic leads people to realise that so much flying really isn't necessary, and actually changes long-term behavior, that could be at least one silver lining.