Finally, there is the role of the meta-buster a.k.a. the anti-meta hero. Cards, combos and mechanics can be individually balanced, but it's far more interesting to let the meta balance itself, as long as no deck or combo is unbeatable. There will also be popular decks and some have a very strong game plan.
Unfortunately Usurper doesent only counter the meta, but also counters other meta-countering decks. As result we see less variety, and more complaints about the balance given how popular Usurper has become.