Ideally, if you spend $35 for a Commander deck, you don't just get the deck but also good cards to grow your collection and lots of opportunities to build different decks with the same cards
You may cast the creature later from exile.) P/T Number 289 Language Italiano Legal Formats Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pioneer, Standard, Timeless, Vintage Not Legal Formats Alchemy, Pauper Rulings (9/1/2023) You compare Elusive Otter's power to the power of any creature trying to block it only as blockers are assigned
Casting a 6- or 7-mana spell pretty much takes up your entire turn
Exile 20 cards from their library doesn't do that much prior to winning, certainly not compared to annihilating them
Apply Marie Kondos philosophy to your card collection and only play formats, buy cards and hang around with people that bring you joy