If someone were to ask me, "What's next after the year of Double Mythic?," I'd respond with trying to gain more tournament experience, and to gain as many top 8 results as possible
Random Encounter This sorcery costs six in Red and then has flashback for eight, and then shuffles, and then mills four and drops all dorks milled with haste to kill that turn
Karn, the Great Creator : While not exactly a Wish card, this colorless planeswalker has a -2 ability that lets you choose an artifact card you own from outside the game or in exile and put it into your hand, which can be a similar effect in artifact-heavy decks
Collecting specific cards from a pool of over a hundred per expansion, and often needing to pull from multiple expansion packs to get everything you need, takes a long time, a lot of luck, or both