[t43562]

Unit tests allow other team members (and yourself in 6 months) to make changes with much less fear.

Sprints are supposed to be a few minutes where we spot early if someone is in trouble so we can fix it asap. The rest of the meetings should really be getting done by your product owner and maybe some kind of team lead. As you say it's usually a result of people not knowing things but sometimes that's the dev team too as in insufficiently well described requirements needing to be clarified.