So how can you organize anything if noone tells anyone what to do? People just suddenly know?
You talk to other people and agree on a plan of action? Have you ever, in your life, interacted with people?
That even if the authority is granted, it’s an authority.
One example doesn’t even grant any authority: A delegate has no authority.
If you OTOH now try to pull semantics and say “but by being convinced by other people of a joint plan of action, they have authority over you”, or “A delegate has the authority to do as they’re told by their council” then you’re doing the “holding up a stone thing”: You make authority such a broad term that not just organisation, but physics itself is impossible without it. Or, in different words: It’s playing dumb. You hear what Anarchists are saying, including their definitions of authority, of distinguishing power-to against power-over, and say “but the stone has authority over you that’s silly”!