[vannevar]

Why would I wait for some meeting the next morning?

You wouldn't. Why are you under the impression that scrum prohibits communication outside standup?

Daily scrum is a floor on communication, not a ceiling. It guarantees that focused communication happens at least once a day. Sometimes people miss slack posts and emails. Scrum makes sure the entire team is aware of progress and blockers. It's a tiny slice of the day when it's done properly.