Powerful spells like Unsummon and Terror were stapled to creatures like Man-o-War and Nekrataal, creating efficient creature rates that made major waves at the time
How you rest is a window into what drives you when no one's watching
All you have to do is wait for a moment where everyones spent their turn developing their board or playing powerful threats, play Mana Geyser, and watch your opponents realize they can do nothing but await the smiting that is surely coming down
While all the other colors would be underrepresented in that particular set, that wouldnt be too bad for constructed formats, and if handled carefully (and adjusting the ratios over time to eventually reach an equilibrium) this strategy could work for constructed
And, even worse, sometimes they intentionally print cards that are toned down because they are worried about pushing the envelope, like most of the split cards in Ravnica and the Aftermath cards in Amonkhet