The Wynn/Encore apparently brought back free parking last year.
The parking charges are a pain. Previously I would just pick up a car at the airport if I were using it to go somewhere like Death Valley after a four-day conference or so. Now it makes more sense to either rent a car at one of the hotels or just go back to the rental car center at the airport.
Years ago, sadly. And it's not just that it's no longer free, it's actually creating more traffic. The whole Vegas experience is non-trivially worse for it.