Citation needed, I think. :) Keep in mind: 1) I "own" some cards in MTGO. That is, there's a line in a DB run by Wizards that associates them with my account

Citation needed, I think. :) Keep in mind: 1) I "own" some cards in MTGO. That is, there's a line in a DB run by Wizards that associates them with my account ID. I can log in and confirm they're in my collection, and I can trade and sell them to other people. It feels a lot like I own them right now, and it's hard to see how that feeling can be notably enhanced. 2) Of course, all that goes away if the MTGO servers shut down, or if my account is banned, etc. My MTGO cards are mine only as long as Hasbro cooperates, which is...exactly the same as if they were using ERC-721 tokens. Nobody else can run an MTGO server, and the hypothetical token showing that my account owns a valuable card is useful only to the extent that Hasbro lets me use it or trade it to others, which they could stop doing at any time. The token has no possible value or use outside the MTGO ecosystem, and if Hasbro has blacklisted the token (or shut the MTGO servers down), no value inside it either. Blockchains can have significant value, but they are fundamentally a DB technology (certainly in this context). There are very, very few times where it makes sense to argue that a game would be better if the devs had just used a different DB tech. And this doesn't seem to be one of those times.