I see some people already taking issue with it in the comments, but I have also been to conferences that helped create partnerships that would not have happened otherwise. I'm not trying to suggest it's worth the emissions or anything, but I agree that being physically present is more conducive to making those connections.
I think a helpful thing would be if people stopped sending people that are just doing it to check it off a list and be done with it. The idea that attending a conference in and of itself is some kind of development is wrong, and people should only go if they're actually interested in participating in the exchange of ideas.