If you buy a Barry Bonds baseball card for $1,000, you don’t own the artistic rights to the image on the card. All you own is the card itself, which has negligible manufacturing cost. It would be trivial for any card company to produce a million functionally equivalent Barry Bonds cards.
When you buy a Barry Bonds baseball card, you hope that the card company won’t dump a million more on the market. You also hope that if another baseball card company springs up and prints their own Barry Bonds cards, people won’t be as interested in that brand of cards. Attention and scarcity drive value; the nuance is that other speculators must care about scarcity along the same dimension that you possess it (in this case: the brand of the baseball card company and the year the card was made). There are a hundred tokens functionally equivalent to Bitcoin, but none approach Bitcoin’s value - purely because Bitcoin sustains more consumer and media attention. This position is fairly stable because attention has strong positive feedback loops.
There has always been interest in speculative collectibles. A purely digital collectible solves a lot of practical problems related to exchange: you don’t have to wait a week to receive the item in the mail, you don’t have to worry about its condition because it does not degrade with time or use, there is minimal counterparty risk due to online escrow contracts, and counterfeits are harder to fake (along the relevant dimension of scarcity, which is the origin address).
People have been speculating on collectibles for thousands of years. Crypto just makes it easier to trade them back and forth.