He is saying that it is a bubble.
Let's take Investopedia's definition of a bubble.
"A bubble is an economic cycle characterized by rapid escalation of asset prices followed by a contraction. It is created by a surge in asset prices unwarranted by the fundamentals of the asset and driven by exuberant market behavior. When no more investors are willing to buy at the elevated price, a massive selloff occurs, causing the bubble to deflate."
We could argue all day, but most of the people that got into cryptocurrencies in the past few months, especially Bitcoin weren't driven by utopian promises to unbanked the banked or banked the unbanked but by the prospect of making money. I know when my roommate got in, he couldn't care less about the tech. He wanted the moon and the lambos. I think it is safe to say that it is a bubble, like almost all financial asset are. A bubble is just a market pattern driven by human emotions. But it hasn't popped. It probably has a long way to go.
I love Bitcoin, don't get me wrong. But if you look at it from a technological stand point it is probably overvalued. It isn't ready for the masses and nothing tells us it ever will. Time will tell I guess.
I watched the video and it didn't freak me out at all. In fact I found it reassuring that he was buying BTC in this dips coz I was too. BTC has changed the world by bringing blockchain to the world. We have oppened Pandora's box, it can never be closed.
I don't think we should get attached to any particular coin and just look for the ones with the best real world applications and uses. Bitcoin might or might not survive but crypto will dominate for sure.
Anyway, you bring up some great points and it feels like there is so much room to grow still. Definitely stay out of tether, you're right about that.