I'm thinking of it more on an org level though - i.e. have one person who all scheduling goes through, with the expectation that they're continuously optimizing everyone's calendars.
That's a very interesting thought. I don't have the opinion that administrative assistants scale well since the idea of "is this meeting important" is really based on understanding, for the person whose calendar is being managed, what they consider important. As you scale it out to a whole org I would imagine that you end up with the same schedule as before - just now the organizers assistant is talking to your assistant. It might deflect meetings from two people of the same rank at an org, but managers can still drag you into meetings where you add no value nor gain no value.
Maybe the solution would be to auto decline every meeting until the person inviting makes a personal case to you, for why you should attend. Every quarter, decline all reoccurring meetings until the case is re-made ;)
When I used to work in ad agency land, there was typically a role called the "traffic manager", which was sort of like a project manager but for the whole creative department rather than just an individual project or two. They would definitely organise everyone's calendars for them, amongst many other things. It wasn't a job I was terribly envious of, I must say!
Maybe the solution would be to auto decline every meeting until the person inviting makes a personal case to you, for why you should attend. Every quarter, decline all reoccurring meetings until the case is re-made ;)