Why do the highest mobility champions also have the most damage?

because you're lying

If we're going by raw damage:

https://champion.gg/statistics/#?sortBy=general.totalDamageDealtToChampions&order=descend

One of them has a dash.

They don't actually, it just SEEMS like they do because their mobility gives them the ability to damage because they can use their mobility to constantly be doing damage.

Leblanc is one of the few exceptions to the rule, but for the most part, most of the higher mobility champions don't have the highest damage.

MUH FLASHY PLAYS [slayer-jinx-unamused]

Originally extreme mobility was limited by lower end damage. That was working as intended.

Well, they fired Morello and Guinsoo.

Because mobility is more often tied to durability than damage now.

Which makes sense. Durability would be tied to heavier armor, which reduces your ability to move fast. But it only takes a knife to instantly kill someone.

because bro. "Balance"

They have higher front loaded damage. Which is generally better in a game where everyone just instantly dies.