The #1 thing to make meetings more efficient is not to have them. Very many meetings, IME, are held for purposes for which a face-to-face meeting is not an efficient tool, and for which decentralized, asynchronous mechanisms like email would serve better.
That means they're unproductive. On the other hand, if you force a venue change, you're just going to get hyper aggressive git commit messages or something equally stupid to show "who's boss". The only solution I'm aware of is to select employees for hire based on likelihood of not being "into" primate dominance rituals, at least not at work. This is pretty hard to figure out at the interview stage and once a company is eventually infected, its plague dynamics time, and much like a bad flu season, work grinds to a halt.
I don't think that's necessarily even a subconscious purpose, but most human group face-to-face interactions end up involving some elements of such rituals, and in the case of meetings they are particularly dominant when the "rich interaction" that is enabled by face-to-face communication isn't used specifically for something else.
The simple two-part question to identify when a meeting is worthwhile and what the scope of the meeting should be (and what should be in other channels): Is simultaneous, interactive, many-to-many communication necessary, and why, specifically, is it necessary? (A followup, to make sure that people are ready to have the meeting -- another common problem that makes meetings a waste of time and results in inappropriate things being done in the meeting venue -- is to ask: "what needs to happen first so that people are ready to engage in that many-to-many interaction"?)
Lots of meetings, IME, are held by one person to gather information from many people or to distribute information from one person to many people -- these kind of one-to-many or many-to-one scenarios are the easiest thing to see doesn't require a meeting (many-to-one being the more inefficient.) There's even some cases of many-to-many communication where there isn't any real need for interactivity. And plenty of cases where a meeting that is held for a many-to-many interactive purpose spends much of its time doing top-down, one-to-many communication for much of the meeting because something that ought to have been distributed to be reviewed by participants to be ready for a productive meeting was instead distributed for the first time in the meeting, wasting most of the meeting time.
If two people can't figure out stuff they should ask third to join them. Then you are having worthwhile meeting. Meeting that are not about figuring out stuff or about figuring out stuff that can be figured by two people are not worthwhile except socially. But if you need social meeting why pretend you are doing work?
