Email chains can fail to converge. Yeah, the meeting could have been an email, but what if it was going to be 20 email back-and-forths? And not everybody is responding quickly?

You ask three people what we should do about a problem. They float ideas. You think the discussion is converging on a solution, and then one of them (who hasn't been heard from for the last three days) suddenly protests where the group is going, saying that they don't agree at all, that they have several concerns, that nobody talked to this other group that needs to be consulted, and so on. Then for that other group, nobody responds for a week because they're busy on something else.

A meeting can force people to say what they have to say, now, or be ignored. That forcing function has value.

And it's not (just) that "people refuse to do anything". It's that multiple people, doing things asynchronously, on different time rhythms, sometimes means that the group consensus advances v e r y s l o w l y, if at all.