Imagine every part of Google is a neural network black box that has machine-learned to say and do whatever makes the company the most profit as a whole, lawsuits deducted.
It could be more of a strategic play to keep eyeballs on Google properties and further build the advertising profile. Also provides a foothold into entering the ordering/delivery/reservation businesses at a much later date if they so choose.
IIRC Google didn't take a cut on restaurant reservations, at least
> We do not receive any compensation for orders or integrations with this feature
It could of course be a lie, but that seems like a bad strategy.