I'm just glad that he talks fast. If he talked like someone I know from east Tennessee, I'd be up all night watching a YouTube video.
Incidentally, they both are relaying the same conclusion about spark plugs.
In my opinion, spark plugs are just a small part of what is involved in having an engine which will run optimally as designed.
Modern engines run nearly forever compared to the engines we are playing with. It is not because of the spark plugs. It is due to computer controlled everything.
Continuous timing adjustment. Spark knock sensors to prevent detonation at all times.
Variable valve time and lift technology.
Continuous fuel/air delivery adjustment. (fuel injection).
The combination of all of these provide a very precise delivery of a clean burning combustion.
A 1960 lawnmower spark plug would remain clean in one of these modern engines.
Conversely, put a platinum or iridium spark plug in one of our half worn out 216 "tractor" engines, and you will not see them remain clean for 200,000 miles.