That said, it grows worse the more tuned the opponent's deck are, and you could face some decks where key pieces are, in fact, with a mana value of 3 or less
After all, wheels are the most efficient card draw spell as well as the most efficient way to discard

Air Nomad Student Alharu, Solemn Ritualist Architect of Restoration Boonweaver Giant Cori Mountain Stalwart Devout Monk Dragon Bell Monk Dragon's Disciple Dragon's Eye Sentry Dueling Coach Efreet Weaponmaster Elsha of the Infinite Elsha, Threefold Master Emissary of Soulfire Enlightened Ascetic Faithful Pikemaster Flamehold Grappler Fleet-Footed Monk Geist-Honored Monk Githzerai Monk Golden-Tail Disciple Graceblade Artisan Half-Elf Monk Hand of Enlightenment Ishai, Ojutai Dragonspeaker Ishai, Ojutai Dragonspeaker Jeskai Brushmaster Jeskai Student Jukai Naturalist Leonin Iconoclast Lone Missionary Lotus-Eye Mystics Loxodon Wayfarer Lyse Hext Mantis Rider Master of Pearls Militant Monk Monastery Mentor Monk Gyatso Monk Idealist Monk Realist Monk of the Open Hand Narset, Enlightened Exile Narset, Enlightened Master Narset, Jeskai Waymaster Oji, the Exquisite Blade Ojutai Exemplars Orator of Ojutai Oreskos Sun Guide Poised Practitioner Pride Guardian Rasaad yn Bashir Reliquary Monk Rhox Bodyguard Rhox Faithmender Rhox Meditant Rhox War Monk Rune-Tail, Kitsune Ascendant Sage of the Skies Serene Master Serra Ascendant Snow Villiers Soltari Monk Soulfire Grand Master Strongarm Monk Student of Ojutai Taigam, Ojutai Master Tifa, Martial Artist Venerable Monk Wandering Champion Wayspeaker Bodyguard Zedruu the Greathearted

You can't wait to cast them later
In all seriousness, this deck is designed to win games very quickly
"Bolt the Bird" exists because of how important it is to destroy it as soon as it enters the battlefield.