They can deal with threats, generate card advantage, and enable powerful creatures
An Amethyst/Steel Frozen deck, or a Villain deck, which could result in any combination of Amethyst, Ruby, or Emerald
1 of 54 Art cards appears in 30% of Collector Boosters
+1/+1 counters are common buffs for all types of creatures in pretty much every MTG set, sagas track their progress with lore counters, planeswalkers add or subtract loyalty counters with their activated abilities and players can lose the game for acquiring too many poison counters, or stack up the energy counters from Kaladesh and Modern Horizons 3
Even retail giants like Amazon have had to install measures like virtual queues for new Lorcana releases to give fans a fair shot at cards
So why is it a card I dont see often enough