>>28016611It's the same system many other card games, such as Magic, use.
You can't realistically patch a physical card game like you can a digital one (Hearthstone). And there are many, many cards that are either poorly thought out, become stronger/weaker than intended as new cards are released, or sort of pigeonhole design choices when it comes to balancing future cards.
Think of a card like pic related, for example. Now imagine needing to balance all Psychic Pokemon around it FOREVER. Pokemon's a 20-year-old card game, you know.
Card games get around having to deal with this problem either with a ban list (YGO) or with a Rotation (Magic, Pokemon). Both systems have their pros and cons.
Rotations don't immediately solve any problems, but if there's something you think isn't balanced or fun, you'll know it'll be gone in 1-2 years. If you buy a full deck, you know for a fact that you'll be able to use it for that full 1-2 year period, no exceptions.
Of course, it also means your deck stops being legal in 1-2 years, which is the main advantage a banlist offers. The problems with a banlist, however, are that they're virtually random and subjective, can ban out your deck mere months or weeks after you buy it, and don't necessarily guarantee a fresh meta.
>or like just a way for them to push people to buy more cards or newer cards?It's primarily a balance issue, just like with a banlist, but it does mean you need to keep buying cards. On the other hand, even in banlist games like YGO, you see new sets invalidating old ones all the time; you can't really use a 10-year-old deck in a serious YGO tournament and expect to win, can you?
