There’s only two camps, investors and gamers. I think that anyone who wants to “have cards that have relative value” are investors, whether they realize it or not. Its one thing to collect because you like something inherent about the cards themselves (I recall a recent Reddit post where the user was trying to collect every single Magic card that depicted an owl in any way). But if your concern is about the monetary value of the cards in your collection, you are an investor, of some kind.

I personally think cards should be for playing, and am pretty opposed to cards being valuable if that means that playing the actual game becomes prohibitively expensive. Standard decks costing hundreds of dollars is not a good thing.