It's still a decentralized market, it's one with a single issuer, as many buyers as want cards, and as many sellers as wish to sell. Much like, for instance, Magic the Gathering. Not a lot of point in selling rare playing cards when they aren't rare, so sure, you could set up a token contract where anyone can issue as many "cards" with whatever properties they'd like. But that wouldn't produce a fun game.
I've personally never been drawn to the rare collectible genre of game, but they're quite popular, one of the services offered is balancing rarity and power. People who like these games enjoy the lottery aspect of buying a sight-unseen pack, opening it, and hoping to score a rare card, they like participating in an aftermarket, and they like putting together decks which other people don't have. All of which can be auditably provided using a blockchain, without having to check for counterfeits, and with players able to confirm that a card is actually scarce just by examining the state of the contract.
There are two reasons not to just make it a centralized system. One I addressed in another comment, the other is that with a decentralized system, it's possible to get the same properties as a physical collectible playing card game.
Namely: the creators control the properties of cards, how many are issued, and enjoy the profits of the first sale. But after that sale, the cards/token belong to whomever purchased them, and that person can sell them to whomever they like.
It's also possible to attach royalties to additional sales, or even retain the right to destroy tokens, but I would advise against this on business grounds, since those decisions would be unpopular ones for customers and players.
Of course, a centralized system would allow the issuers to confiscate the assets at any time, or forbid their transfer, or change the arrangement so that people are lured in with the premise that they can freely resell their cards, and then impose some cut of the resale price ex post facto. Plus if the company goes out of business, and shuts down the database and servers, that's the end of all that, your supposedly scarce bits are now useless.
So if your definition of losing control involves not being able to abuse your customers in that way, I can see why a centralized database might be preferable.
If it doesn't, then a centralized database is clearly inferior in every way that matters, for this application. Of course, someone starting with a thesis that blockchains are useless by definition, is going to begin with the conclusion, and work their way backward looking for reasons that conclusion is true.
