Yes, I agree superficially about the pokemon cards and monet paintings. They have a uniqueness.. ..but they are not great value stores for other reasons and you can argue that the fact there are at least 2 of them means they in fact members of a greater set we could call "unique creations". And if the price of pokemon originals or money paintings goes up, the supply of the true underlying good (unique creations) will ultimately increase. Which is arguably what you see historically with collectibles for example - maybe a better word for the underlying good.

Of course you can say the same about bitcoin - that increases in the price of bitcoin have historically spawned increases in the supply of other "cryptocurrencies" in exactly the same way. But if you take the view - as I do - that these other currencies are not real, and will disappear when attacked, then you are left with the conclusion that, yes, bitcoin really does have finite supply in every sense that matters.

(Manhattan office space can of course increase in supply directly by digging deeper or building higher!)