If your friend is consuming massive amounts of other dev time in PR reviews, maybe he has other issues. I'm willing to bet even without agentic coding, he would still be problem for your coworkers.
Sometimes I do broad throwaway tasks. For example I needed a rust lambda function that would do appsync event authorization for jwt tokens. All it needed to do was connect to aws secrets, load up the keys & check inbound requests. I basically had claude-code do everything from cdk to building/testing the rust function & deploying to staging. It worked great! However, I've certainly had my fair share of f-ups like I recently tried doing some work on the frontend with claude code and didn't realize it was doing useEffect everywhere!! Whoops. So I had to adapt and manage 2-3x claude code instances extremely closely to prevent that from happening again.
To be effective with agentic coding, you have to know when to go high level and low level. And have to accept that sometimes agentic coders need a lot of help! It all depends on how much context you give it.
Are you doing a lot of broad throwaway tasks? I’ve had similar feelings when writing custom code for my editor, one off scripts, etc but it’s nothing I would ever put my professional reputation behind.