I mean, you can certainly make straightforward routes for every dungeon that are timeable to at the very least 20s. The problem is if something goes wrong along the route, you will get flak for the route if it is not the “meta” route. That said, the meta route is often cancer in a non communication pug, the problem is the DPS never realize it. Then when a mistake happens in the straight forward route, the tank is getting the flak.
Or sometimes some healers/dps just can’t handle the route. Either because the healer isn’t good enough or the dps don’t know how to kick/cc the mobs. Then when you do this big pull that you know is doable, but the group fails for the aforementioned reasons and you wipe, tank is getting “why the hell would pull that much” even though it is a perfectly reasonable pull. Or on the flipside there is a pull that is barely doable in a pug, but usually results in a wipe, you don’t do the pull because you know it’s usually a wipe and the dps “why didn’t you pull all that?” (it’s always the dps) or worst, you don’t do the big pull because you know you don’t have CDs for it, so you are doing a medium pull until cds come up, and the dps decides to pull for you, and you die because you didn’t have cds.