In order to push back against the reliance on two mana rocks with a disadvantage like Charcoal Diamond that are heavily played, WOTC has been printing powerful three mana rocks like this pair that tap for any color of mana and then add powerful extras like Decanter of Endless Water
This method appeals to fans who have favorite types or want to build type-themed decks quickly
Savage Summoning Savage Summoning costs 1 mana to give a creature spell flash and make it uncounterable
It's strong everywhere, but it has enhanced value in archetypes that care about counters generally, +1/+1 counters specifically, proliferate tricks for multicolor brews looking to add loyalty counters for their planeswalkers, four and five-color decks, Commanders with evasion, Commanders with a power that, when increased by 1 get a faster kill, Equipment, Aura, and Voltron decks looking to get in kills with their Commander, and loads more
Many Magic players widely recognize and agree upon established cards for each format, and some cards see use in many formats