Right clickers in urf?

I thought the point of the mode was to take away cooldowns and mana restrictions. Why are champs who solely right click like Kindred, Yi, Trynd, Udyr, Trundle, and any marksman so broken compared to a champ who would benefit from the buffs? I saw a Kayle and an Udyr 1v1ing turrets and winning right after they killed everyone. Even Ezreal gets destroyed by anyone who builds lifesteal and auto attacks him a couple times. I'd rather just play Ascension or the other Dominion mode since the whole point of ARURF is kinda boring.