At the low cost of one generic, one blue, you could very quickly build an army of Persistent Petitioners
Holding up two mana is a lot, and holding up two of the same color when youll need that colored mana to cast permanents (or maybe not even have enough to do both, thanks to having other colors of lands to run)
Many decks are built with two types in mind, but finding enough Pokemon to fill only those two types, and synchronize nicely with each other, would be laborious at best
Surge Conductor does it any time a nontoken artifact enters under your control, and the Peacemaker does it any time your opponent commits a crime
Unlicensed Hearse, meanwhile, staples inevitability to Crook of Condemnation, which is something I didnt realize I wanted
Optimized decks can probably drop these in favor of more 1- and 2-mana acceleration, but these are still staple-status for casual Commander decks