On the opposite end, if you only put big, beefy creatures in your deck, you wont be able to play anything for the first 3-4 turns of the game
However, most larger formats have a multitude of cost-reduced spells, such as the engine offsetting the cost of Pitch spells, letting a Beanstalk player accelerate through their deck without losing on the tempo axis
Christopher Ecclestons Ninth Doctor has the Haste ability, which enables the player to use the card to attack or perform actions immediately after theyve played it
Without Yawgmoth, Thran Physician, Golgari Yawgmoth would not exist
Mindstone can be that step and then it is pretty irrelevant, if you can make 9 or 10 mana mos of the time won't make much difference while an extra card really can