My experience is that it's even worse: they've already produced enough code that the codebase matches their taste and theirs alone.

So in essence you have one guy working at 4x and e.g. four other getting just 0.7x - net effect is still positive, but everyone save for that one person is miserable.

Mind you, the 4x dev doesn't necessarily have to be particularly talented - they only need to get their foot in the door before anyone else.

Back during the ZIRP days you could immediately tell that this is the case in a team by staff rotation alone. Nowadays people understandably cling to their jobs, so you might now know until it's too late.