In fact, a smaller boat is preferable due to its maneuverability. Little Goose Creek runs like 400 CFS max. Admittedly it's some pretty gnarly creeking they are doing and some serious rapids and waterfalls, but it's not the same thing as a big water river where you'd want an 18-22 foot raft. A big water river is often running at like 30,000 CFS. So 75 times the volume.

Here's Cataract Canyon at highwater (probably around 50-60,000 CFS if I had to guess). The J-Rigs in this video are 40 feet long and are doing tail stands in the rapids because the waves/holes are so large. A 10-foot boat would get eaten for lunch.

https://www.youtube.com/watch?v=3afnsJ2VPaY