OT but if I never see connection handling and connection callbacks mixed in with React components and stale state refs in a real, production app I'm responsible

OT but if I never see connection handling and connection callbacks mixed in with React components and stale state refs in a real, production app I'm responsible for.. It'll be too soon. Alas, since it's being "promoted" in the React doc examples I'm guessing I haven't seen the last of this :| On-topic: I read all that and have no clue what useEffectEvent does. Why can't I just use a closure? Passing the effect event is listed as a limitation, but it's never explained why it can't be passed. What happens?