If there's a cost associated with having Ursine Monstrosity attack the chosen player, you aren't forced to pay that cost, so it doesn't have to attack that player in that case either
If you really try, you could maybe say that Shadowbringers is about countering the end of the world, but thats really a stretch
Stoneforge Mystic no longer finds Colossus Hammer (or anything else), Archon of Cruelty is just a big flier and no longer wins the game for Creativity decks, Primeval Titan cant tutor up lands and gets blocked by Elesh Norn, Mother of Machines for days, Omnaths landfall ability doesnt trigger - the list of popular decks and cards that Elesh Norn stops is surprisingly long
Sewer NemesisSewer Nemesis and UchuulonUchuulon both have varying stats based on cards in graveyards or creatures on the field, respectively
Its cheap, easy to cast, hard to interact with, and its one of the most played blue cards in the format