Remathilis
Legend
Why would you assume it wouldn't have downside? We could easily add them in a way that fits the theme. The Warlord gives someone the benefits of Haste? Well then they get Exhaustion right after the duration and the duration could be shorter too. Frenzy is basically a low level version of haste and people don't even use it.
Because nobody ever mentions them. They say "it's like magic, but it's nonmagical" and when pressed it never goes farther than that. I'd like to hear more about how that gets balanced besides Martial Christmastree land thinking. @EzekielRaiden at least provided some thoughts on balancing them. Most of the time, it's just all the power, none of the (scant) drawbacks.