I know this is HN, and my instincts tell me posters here predominately are either ICs or managers "in the small" (line level, or at the most at the scale of the OP, in which the company is ~300).

That said, asserting that most meetings are either brainstorming or decision making, is naive. When an organization grows beyond ~100-150 people (Dumbar's Number) the org must metastasize into smaller, "self-contained", orgs that are far less than that number. Once this happens, there is need for meetings that drive accountability, closure, and alignment at scale. For example, monthly or quarterly business reviews.

These are NOT brainstorming meetings or decision-making meetings. They are meetings where leadership drives accountability and alignment by ensuring light is shined (in a way visible cross-org) on the right topics for the biz.