Urabrask / The Great Work Storm wants you to cast a ton of spells in a single turn
Anyway, Sinkholes ability to disrupt peoples mana before they can really even get their game going is good enough for Legacy and would be seriously problematic if the card was ever legal in Modern, let alone Standard
Each standard-legal set since Ikoria (except Core 2021 ) features 2-5 Commander decks, as the Commander format has become one of the most popular ways to play Magic, releasing preconstructed commander decks with every set allows for the creation of cards unique to the format that are thematically tied to the setting of their respective expansion, as well as giving more options to new players who want to try Commander
In this deck, you'll find powerful magic users who take center stage in the Amethyst portion of the deck
If they do, you get it Zombified under your control
I've also seen people write on basic lands to note the card (though this isn't allowed in tournaments)