It’s a tough thing to balance because ramp specs tend to be good at longer fights like raids and higher keys.
It’s more the nature of a trash pack. You want as much damage as possible to blow it up before you run out of defensives and stops. And the easier the content, the shorter that pack lives, which makes frontloaded burst damage so valuable. And in mythic+ specifically I’d wager most people don’t even do keys high enough where ramp specs can shine.