I'm not familiar with other CCGs. Does Overpower have an exceptionally high number of useless cards? Between some of the universe cards and a lot of the weak specials, it just seems like a lot of cards with great art are wasted. Is this just common in CCGs with expansion sets and developing rules?
Most ccgs these days design cards with a few factors in mind that, in some cases can render cards "useless" but in other cases they are sought after. Almost every card game has cards that are considered useless based on the normal deck construction rules and the back and forth of the game format, but some games have different game formats that tends to make some of these "useless" cards more playable simply by limiting the amount of any given card to appear at the event, thus forcing the players under such formats to use these cards they normally would not due to the lack of card pool and the difference a minor edge can give.
If you were at a tournament, where you were limited to the cards that you drew out of 4-5 packs to build your deck exclusively (either a sealed deck or draft event), you'd see a lot more basic teamworks being used across the board, due to needing to add them to make your deck legal, and in those situations where some of the best cards are not available, a +2 or even a +1 on a single attack can make the difference. Venture plays would be shifted drastically due to the lack of control one would have with a deck built from such a small card pool. Granted, these styles of variations wouldn't work with Overpower at all, since you can easily open 4-5 packs of cards and not pull a single hero card, or specials would be spread too thin, not netting more then a single special for any one character. It would drastically effect who made up your team and why.
But back to the original question, in many other ccgs, dead cards are just as common, but the developers have found ways to make them playable by putting them into a completely different format of play.