I'd actually be curious what the process for making one of his production are.
He's been around long enough that surely he has an assistant or team of employees helping work on his stuff by now. He might not even be responsible for the scrips, I know that can happen to some channels as they get larger. Knowledge hub, Alt history hub, the various off shoots of Simon Whestler's Biographics show, Game Grumps, Russian Badger, etc are all managed by entire teams, and the figureheads for them pretty much just own the channel, outsource the editing and come in to to the voice over once they have enough money to keep a staff on payroll.
Regardless, eyeballs on content isn't directly corelated to quality of information; it's good to look at some of this YouTube history stuff to help get introduced to a topic but always super enjoyable to actually dive the topic through primary sources if access can be had to them. Some of the older design documentation is declassified now.