Yeah, trading cards only drop once the game reached a certain amount of users and Steam Card Exchange only picks up data that exists, like for example it won't showcase a level 5 until it's been crafted.

That's exactly the false tag that MinaVictoria is referring to.

For some reason, Steam has developers set that flag themselves rather than setting it automatically based on whether there are cards or not, so there are a few games that have cards but don't say it, and a few games that say it but don't have cards. This is further complicated by the forced delay to trading cards being released, so there are also games that say they have cards, but don't, but will when they can.