Hearthstone

Hearthstone's contribution was designing cards that could only work digitally, random effects, hidden transformations, board states that recalculate themselves, instead of adapting a physical game. That freed it to be faster and stranger than its paper ancestors, and it is still the most polished presentation in the genre.

The honest caveat is cost. Constructed play requires a collection, and building a competitive deck from nothing is a slow process or an expensive one. The counterweight is that Battlegrounds, its autobattler mode, needs no collection at all and is arguably now the better half of the client. Arena drafts sit in between.