Simple due to unique debuffs brought by each class they will not replace each other entirely. Rage of Halone, upcoming Storm Path debuff. I do not know where you got the notion that over a course of a long fight not having 1 damage debuff wins over Warrior slightly advantageous if meticulously timed CD. Aside from that Speedruns will never be a Warrior's thing due to having only 1 dependable non charge up defensive CD, and without Flash blind things do not go a Warrior's way aside from TP starving.

In order to do Speedruns warriors still have to use way more gear than Paladin. As of current state Paladin is capable of Spiritbonding a full Militia armor and Accessories while running Wanderer Speedruns, even after 2.1 Warriors won't be able to achieve that feat. (I'm talking healer and other party members aldo do at least Accessories Spiritbonding while doing Speedrun).

But yeah if you meet some elitist in a one tank content your probably hear Warrior could do this and that come 2.1. But are they gamebreaking? Not really. Unless we're talking 5 Stacks Everybody's Grudge every 20 seconds...