If you don’t buy anything, understand that you will sit and lose 8-9 times out of 10, no matter what deck you manage to build over time. Either opponents with a much stronger deck will be fielded against you, or opponents will receive cards in such a way that you simply cannot do anything. Any card of yours, even a strong one, will be immediately destroyed, and you will have nothing to oppose even the seemingly nonsense card of your opponent.
At first it’s interesting, but then only for those who are ready to pour in money, or for those who like to be a whipping boy.