[dredmorbius]

"Is the the best possible use of our time, collectively, and/or of each of us, individually, for the organization and our collective goals?"

I suspect you'll find that more effective people tend to recognize when they're in a meeting they 1) don't need to be in and 2) which is keeping them from doing something more important.

Socializing, strengthening group cohesion, and other organizational (as opposed to individualistic) objectives may mean that even if you personally perceive greater benefit at being elsewhere, the organizational / collective goal may still trump, which is why that's included in the metric.

The concern isn't to do a thorough evaluation where that's not itself cost-effective, but to use the correct basis for measurement. Deciding on imperfect information is perfectly acceptable. Deciding on the wrong basis should really be avoided where possible.