It's called a block knife. If you look at the way wooden shoes are made those typically have a bit longer blade but it looks very versatile. Reminds me of a tobacco cutter or cheeese wheel cutter. You can see where in the block knife picture a draw knife could easily be modified. The addition of a curved blade just multiplies its usefulness.
cheese-wheel-cutter.jpg
tabacco-cutter.jpg
block-knife.jpg
Our inability to change everything should not stop us from changing what we can.
Interesting bloke - I enjoy watching his videos. He has a forge, makes a lot of his own tools, built a cabin in the woods days from the nearest road, built a water wheel, canoe, pond . . . Long list. And plants lots of trees. I think he would have earned a few Iron Badges by now.