Very realistic with his statements. Obviously, it is becoming obvious the level at which people are beginning to see cryptocurrency as a get rich quick scheme and forgetting the main essence for which most of these coins or tokens should be existing. Most investors usually do not even end up doing a proper investigation on an asset before investing and some may even decide to go all in.
The crypto space is still very risky and like he said, volatile, so, going down to zero for some, is not something that should not be expected.
His discussion is not a new one, nor is it a discovery that emerged during the crypto hystory alone. So, Vitalik haven't told me a thing I don't know.