The big contradiction I see is what he says in the first minute, that modern companies are only concerned about making the next quarterly earnings call. If that really were the case, they wouldn't care about age. They would in fact be more eager towards hiring older people because the younger ones tend to be lazy and have weird work ethics, and I would even say some mental problems.
So, actually ... the bias and perception is in the opposite direction, where they believe that older people are "low energy", often just trying to coast to retirement, and of course their salary expectations are higher, whereas the younger ones might be eager to prove themselves, will work harder, often being single and therefore have no problem working late and weekends regularly (for free of course, since the label them "exempt"). There's also the adage about teaching "old dogs new tricks", where they believe younger talent might be more malleable to being molded into their corporate vision, and, frankly, I would hesitate hiring an older guy myself. Why? I know LOTS of these older guys who haven't bothered to learn anything new in the past 25 years and simply didn't care to do so.
I'm on the high side of my 50s and, even though I haven't been laid off yet, I have posted my resume to about 2 dozen jobs over the last few months, mostly remote, but a couple even local in the area here. I think I got very quick dings on about half of them, got exactly 1 interview (and got dinged), and the rest didn't bother to respond. I used to get a ton of interest, just because I have various things on my resume that sound really cool ... "Lead Software Engineer at NASA", "Systems Architect", "Enterprise Architect" (the last 2 at Fortune 100 banks, etc.). So just having those on the resume has always elicited many responses ... but not anymore.