Yes, reviewing things make things slower. Not reviewing them produces horrible results. There's a balance to be found and it depends on the team/org.

I hope we shift engineers closer to users than ever before. Get them to understand user's needs and the actual product more - they'll write better plans and prompts. Review the plans.

Code review becomes less of a thing when the team's on the same page, so regularly align on what the goals are.

Accept post-merge code reviews. Things slip, normalise coming back and saying "actually, we should have done this differently". It's not a bad thing, you're learning!