I dont really understand economics, I don't know for certain - I watch these things like a passenger strapped into the back seat of a kamikaze plane, eyes bulging wondering when death will be coming.
But my understanding here is its not about whether bubbles ever existed before, its saying the structural mechanisms underpinning finance capitalism have fundamentally changed post 2008, with too-big-to-fail socialism-for-bankers putting a floor below the whole enterprise, endless QE, buybacks etc etc amongst other factors fundamentally changing the logic of action.
The result being that the finance system is spinning further away from real-world reality, where in the past some unemployment news or productivity figures were so pivotal, into one that plays ever increasingly by its own internal rules.
I don't think YV is saying the split between the two worlds is total, he's saying the worlds are moving further and further apart - profoundly decoupling. Supposedly some older speculators used to making judgements on certain orthodox 20th Century understanding of markets have been caught out during Covid.
If you think he is wrong perhaps ask him on Twitter? He's quite responsive from what I can see. id be interested to know what the answer is.