Show me where I said it was the best? I said Arms is good in reply to someone saying Arms is a bottom 3 spec, which is flat out false. Also warrior no longer has some uber advantage with execute, a lot of classes have execute mechanics now.
Also, this obsession with single target DPS is just hilarious. Like every single boss is just some target dummy that you wail on for 5 minutes. Burst AOE and strong cleave are both incredible things to have in Uldir and Arms is great at both of those. But yes, lets focus on single target and only single target.