The people that show up also probably spend more if they paid for the reservation.

I’m a little curious why the restaurants don’t just charge more. From my simplistic understanding of economics, this sounds like consumers are willing to pay more for it, but restaurants are letting scalpers eat the excess. There must be a reason, they know the market better than me, just curious what it is.

Restaurants want to be as busy as possible as much as time as possible and to sell as high value produce as possible and tip the waiter well. And to come back when they're not booked up.

Scalpers just want to skim a margin off the top at peak time, and don't give a shit whether people think they've overpaid for the experience and end up skipping dessert and ranting about how mediocre it was on social media. Or indeed whether they actually sell all the reservations at all they haven't paid for, especially if the profit maximizing fee is one that leaves it half empty...

I’m curious about that too. My speculation is they think there aren’t enough people to fill their dining rooms who are willing to pay that much more. They could probably do something like auctioning off a certain number of last minute reservations, but then they risk looking predatory.