oh no I want wizards to make half a passing thought about the consequences before they print obviously busted nonsense, the horror

like cmon, it would've taken someone like three and a half seconds for them to look at underworld breach and say "hey this looks broken with literally any cmc 0 spell with text, maybe we should make this exile things instead of letting it just put them back in the grave"

it turns out that the list of things that are fine in standard and broken in eternal formats is pretty consistent. if it interacts with LED or low-cost cantrips profitably, it's gonna be medium to unplayable in standard and probably very good in eternal formats. if it's a cmc 3+ thing that provides too much value in a midrange mirror, it's probably acceptable in eternal formats and too good for standard.