There are many other knots used commonly in climbing and he named a few. You cannot tie off a three way anchor with a figure 8, a bowline is not safe for human weight because it can invert, despite being used for thousand pound logs all day everyday at my job... And it's funny he called it a reef to me, all my sailing buddies call it a reef, all my climbing friends say square, and hardly use it. A sheet bend is really hardy for hauling loads up the wall, a prussic for a repel device, and an alpine butterfly for tripoint anchors.
Edit: this is more about Trad climbing than sport or toprope. If you didn't set the anchor on a toprope and your guide/partner isn't into carabiner/harness setups, yea you're gonna tie a lot of double 8s
I am a few stages into the knit obsession, I own the Ashley Book and have a couple project knots displayed in my house.