You open a frontend pull request. The diff is 400 lines, an AI agent wrote most of it, and the description says "adds the checkout flow". CI is green.

You read the diff. It looks reasonable. You still have no idea what the UI actually does.

So you do what you always do. You pull the branch, install dependencies, start the dev server, and click through the flow yourself.

Ten minutes later you approve the PR.

That ten minutes is the bottleneck now.