I think comparing it to recent online scam behavior in the crypto and NFT markets makes a ton of sense. Cards bought for lots of money are (literally) non-fungible tokens. Possessing and showing off a graded whatever is a display of embodied social capital.
The important part of the quote which you conveniently left out is "convincing." The market is inflated by hype and shows similar resilience to FUD thanks to big name creators and small communities of MTGFinance types. You don't have to agree, that's fine.
Why does people disagreeing with you get to you so much? It's really obvious from your tone that you're angry, but this is a pretty low-stakes forum. Nobody is making you defend anything. "Go outside" only works as a constant refrain against people who don't go outside, but Pokébeach has, for more than a decade, consistently demonstrated a sensible user base with lives outside of the hobby. I'm one of them, and I'm sure could be too, but your disposition in this thread makes me think you don't have any other outlet for your feelings.