Both are running automatics. That pause between 2-3 (Corvette) is by design in order to protect the transmission. My Hellcat does the same thing, just not as pronounced. Notice that the 3-4 shift is instantaneous and if it were a 7 speed manual, the Ford would have jumped forward a couple of feet at every shift. It doesn't.
That's either a sick Z06 or the F150 has a lot more than just a supercharger bolt-on. Not taking anything away from it; it looks pretty quick. Just saying. And roll racing may seem gay but who's going to stop in the middle of a busy interstate, take up 2 lanes, line their cars up and then have someone honk or flashlight them off? That's what you do out on a dark, isolated road. In the middle of traffic, if you're gonna race, you roll race.