the reason they balance for cooldown is because the devs are unironically afraid of the concept of a skill floor existing and alienating people who give up when they arent good at something on the first try. sojourn was the first victim of this, with her kit clearly being based around rewarding good aim, only to have that made less and less important as seasons went on (even if some of it was mercys fault). a lot of abilities in general would be far less annoying to play against if they werent so mind numbingly easy to land, hook and sleep dart especially