That's not completely true. The amount of resources wasted per hour are proportional to the value of the coin. Lacking any genuine uses for for cryptocurrencies, people determine coin value by things like transaction volume, market capitalization, influencer endorsements and active wallets instead. Thus every additional user, transaction and especially the common million-dollar wash trades designed to pump their respective projects, contribute significantly to the waste that is generated.
One single entity being the source of truth will always be cheaper than a blockchain verifying a transaction. The caveat is if that cost is worth it.
For buying tangible goods, the gas price might be worth it since Visa/MC control what you can sell online and payment processors can be circumvented using crypto. That is a pain point.
For intangible goods, the gas price is simply not worth it. What pain point exists for owning digital goods that would require decentralization? In my opinion, none.
They create images and sell them on someone else's network. I could list a JPG on eBay without having to run any infrastructure either.
What really happened here was that the company that launched this did it in a way that congested the ethereum network and an auction essentially occurred in "gas" to use the network for this purpose for a couple hours. Instead, the company should have pre-allocated guaranteed minting on a lottery basis so it didn't devolve into a "gas" auction or, increased supply to match demand, which they knew in advance (like you said, limits here are artificial).