I'm not a pilot so take this as you want. I am, or was a champion powerboat racer.
If you watch he was digging in his left sponson most of the way. He never developed the speed necessary to get up on step and when he saw the seawall yanked it into the air, banked, where it looks like he just ran out of speed. If he had lined up and kept the plane straight down the lake he should have had time to get in the air. The curving track he took created massive drag.
Yes a little chop would have helped. Any boat will be faster with a little chop than a slick, dead flat water.
Yes ground effect counts too, very much so. Racers work with it to a point when we run a kilo straightaway run we float the boat with only the prop in the water, no part of the boat touches the entire length of the run! The trick is letting it back down. Imagine 125 mph 8" off the water.
The pilot screwed up