That’s a possibility indeed, but at least he documented all the steps, it’s great to see that because it looks like a lot of work. But I agree at the first that big long page for sure can be intimidated (CTRL+F is your best friend here).

He doesn’t look like someone who doesn’t know docker, there is a whole section on that wiki page where he describes what docker is and how it works in details.
He just decided to not dockerize his installation because:

1. he thinks VM in his case are more practical.
2. docker didn’t even exist when he started to go self-hosting.