I actually almost never use pre-mades. For the time being, I am in a PVE guild (no one else even has a full set of partisan let alone conqueror). I play against pub/imp premades. Sometimes my pug wins, sometimes my pug loses. Yesterday I was in a zone where the highest hps on my team were 25k, I currently have 30k as a sorc. It didnt matter that I was the top healer in the zone, it didnt matter that the other team had no healers, my team simply could do nothing to them.
And from my perspective, the team with the best dps is more likely to win than the team with the best healer.
If you have 6 dps that are better than my 6 dps, it likely wont matter if my 2 healers are better than your 2 healers. The reason is, you are outputting way more damage way quicker, so your healers (even though they are worse) can keep up with bad dps, where even the best healer cant outpace focused top end dps.
If anything good dps + good gear, is really the ticket to winning. But many dps are not running full expertise and then wondering why they cant kill the healer who has more hp and more expertise.
Heals are very overpowered right now that it's not just premades running a lot of healers, though obviously premades tend to be the biggest culprits. 1 healer is fine. 2 healers is boderline manageable. Anything more than that you're getting into the staring contest range. Even with 2 healers a lot of fights are going to come down to the fact that you team killed their healer twice instead of just once for your healer and no one class should have this much impact. Of course it does boil down to DPS, especially since healing is now super easy for non Commandos that even bad players can do it fairly well. But it'd usually boild own to ways that have nothing to do with killing the opposition, and a WZ where the node never flipped control is just not very exciting. But people have to die first for things like that to happen.