But more importantly, who does not get to travel much, or at all? → Scientists at less wealthy institutes or in less wealthy countries; those having to deal with lengthy/complicated visa processes; those with care-taking responsibilities; and those with disabilities.

What do we conclude from this? Making meetings more sustainable can make them also more inclusive, because if we make meetings at least hybrid, or even fully virtual, many barriers fall away. However, virtual attendees must not be treated as second class participants!

Ditto amateurs. I've attended meetings in the UK but no further. I may consider European venues if the meeting was interesting enough. Intercontinental flight is right out. I'd rather spend my money on equipment.