Magic creator Richard Garfield may have had innocent intentions when he decided to distribute his new card game primarily through randomized booster packs, and to make stronger and more exciting cards less likely to appear in said boosters than the common chaff
Colorless Both Magic and Final Fantasy combine technology and the arcane, whether it be Cait Sith or Karn, and, of course, tons of swords, guns, gunswords, swords with guns attached, and guns made of swords, so we should see an interesting array of colourless cards on offer
So they ended up with flashback, but you can tap a creature to cast it for cheaper. WotC considers flashback as deciduous, or a mechanic that they plan to reuse fairly often (although not in every MTG set)
That may seem simple, but it did facilitate some combos back in the day
[5] Ryuji apologized to his father for not getting revenge and found himself unable to hate Yugi