Typically digital game assets have gone down in games over time. Game developers typically will continue producing a item or produce other items that weaken the desirability of popular assets. It's a way for the company to capitalize on desirable asset. In Steemmonsters case they reward play with cards and fund their business with yet more cards. In addition if a card becomes popular and or powerful the newly incorporated cards are designed to reduce the cards power to make things "fair". I'm not seeing anything at this time that suggest the cards will appreciate in value.

In regards to having control of the asset. That is a plus and there is a active buying/selling market. That's good. However, if the company stops developing the game it will soon fold and the assets will be most likely worth zero.

I believe there will be a breakout crypto game at some point. Then we most likely will see what the true value of a blockchain game. So far all I've seen is the old school approach.

I do enjoy playing the game!!