I've often wondered the same. My local is roasting big batches and selling them same day, and using them the day after roasting in their own cafes (the only delay being dispatching wholesale orders first before taking the rest from the roastery to the café).
I have been amazed how, with home roasting, it is so clear that resting is useful. As they rest they get more tasty. But it seems clear this doesn't happen in commercial roasting, at least from what I've been told when I've asked.