This is not just a great way to get blockers out of the way by making your opponent sacrifice them
Combos like Vraska the Unseen and Bloated Contaminator, or endgame cards like Kamahl, Heart of Krosa take time to set up
Heck, theres probably a great Naya Dragons deck with Thunderbreak Regent and Draconic Roar as one-of, if not the only non-creature spell in the deck that works off of the creature-mana produced from Shaman of Forgotten Ways and Beastcaller Savant
If youre specifically looking for the best colorless cards MTG has to offer thatll let you make high-level plays via easier setups, then youve just found one of the highest-tier ones there are
The greatest supply on a card is almost always 2-4 months after release, when the next big set comes out
Those effects usually have some redundancy, and they may already be in your decks waiting for these artifact untappers to appear and break them