“Computers operate on electricity.”
You don’t say.

“Case and power supply, generally speaking, won’t really affect the performance…”
The latter is somewhat true, but the former is not. PSU is probably one of the most important things, that affect all the other things in your computer. Which he later acknowledges.

Bottom line, dude got too much fundamental\basic, and talked about stuff that you don’t really need to know to “build” a PC. To physically “build” computer, you don’t need to know about binary, and shit.
Knowledge about static electricity, on the other hand, would be helpful (fortunately he’s getting to it in the second part).