I will also add that time of year makes a big difference. If the parks are closing early at 8pm, and the high of the day was 68 degrees and sunny, I don't want to waste 90 minutes inside a restaurant having dinner. Not only do I not want to sit inside and freeze in the AC, but I also will likely end up missing the nighttime show at whatever park I'm at. I'd much prefer grab a QS dinner with patio seating or stay until close and dine somewhere after the park closes.
Now when the park is open until 11pm, spending 90 minutes on dinner doesn't seem to be so much of a time suck. And when it's hot, we often aim for a lunch table service to get a break from the sun.
The truth is that EVERY restaurant has availability at the last minute - you do not have to box yourself in with reservations way in advance. Make the ones in advance that are important and if your family needs a break one day, jump on the app and make a reservation