I just watched that guy’s video, finally. He’s full of crap. 
Aging demographics is disinflationary. He just focused on supply of labor. He forgot that seniors consume less. Just look at Japan. 30% of Japanese are over 65. They don’t go to bars, don’t need to buy fancy clothes to impress the opposite sexes. They just need to spend on adult diapers.
He pooh poohed the disinflationary force of technology. Well good luck with that. It doesn’t need to be fancy pants AI robot replacing humans. It can be in the form of tens of millions of gig workers like Uber and Doordash drivers making less than minimum wages. Technology also shows up in each worker being slightly more productive year after year, so you need fewer of them.
The guy is careful not to give an explicit target for his “secular inflation” call. Maybe if we see 3% inflation he will come out and declare victory. Bear in mind we saw inflation over 10% during that 70s period he is so obsessed about.
He will lose his clients a truck load of money in the next 10 years. 