Ryan's approach of using a chopstick is centered around a few things. First the chopstick is typically sharper and has a hard edge and a soft edge (bamboo outside vs inside). He mentions that a sharp edge will create a cleaner cut for better healing. I'm no botanist, but the idea makes sense to me. Hitting something with a dull point will "bruise" the root compared to a clean stab or cut which would heal better. He also mentions that you aren't inserting it an pulling, but it is a much more loose scraping of the outside layer of soil. Another things is that when he detests the root hook/rake, he is aiming at the insertion and pulling/yanking of roots to pull them free (which you can do less effectively with a chopstick, and I'm assuming he is generally talking about more refined trees. This rips the roots and does not provide an environment of healing to recover quickly.
He also lauds the chopstick as a more effective way to insert soil as opposed to a metal chopstick or other tool without a slanted angle at the tip. This allows it to function in a way that actually pushed soil into the pot rather than create holes.
All that said, I think there is a time for younger, vigorous, root bound nursery stock to be met with a root rake to save you tons of time and work. If you've ever used a chopstick on a severely root bound nursery stock plant you'll see what I mean. Two different tools for different purposes. I don't tease out the root from my collected yamadori with a root rake before potting them into pumice, but I also don't reduce the root ball of a 24" box olive tree with a chopstick (probably a sawsall or chainsaw tbh)