It doesnt make a huge difference in 2-color decks, but 3+ color decks love this for its low cost and easy fixing
As for Kykar itself, I expect a price closer to $5 than $10 by the end of the year
Hydra Omnivore , Multani, Yavimaya's Avatar , Worldspine Wurm , and Ashaya, Soul of the Wild are big monsters that can be played the hard way but are much better to cast using Zimone and an extra land drop courtesy of some of the supporting spells , like Rampant Growth , Cultivate , or Explosive Vegetation
Pick up Teferi, Time Raveler at TCGPlayer #4: Helm of the Host The second Equipment Artifact to appear here is costlier in mana than Sword of Fire and Ice, but its abilities are just as impactful
Final Fortune + Last Chance + Warriors Oath Two mana for an extra turn is an insane rate