Ultimately, in my experience, it often requires both. Written and oral communication.

Some don’t listen, some won’t read. It’s not only a function of the specific person but also depends on the day who reads and who listens.

So, yeah, in theory, in an ideal world with perfect co-workers you wouldn’t need so many meetings.

In the real, messy world we live in, meetings are one tool to make sure important messages come across.

I'd just add that, in my days at larger companies in particular, there were a lot of things that were were probably vaguely useful for me to be aware of, but if someone dropped a document about initiative XYZ in my inbox, I probably wouldn't have read it. But I would have gotten the highlights at a regularly scheduled meeting.