Some of these things are hard to automatically judge. Tanks using cooldowns properly, for example? How does an algorithm judge that? Does SE have to sit down and decide "you should triple pull and use Hallowed Ground here"? That seems impractical. Healing done is another one, because healing done and HPS skyrocket in a group that's taking more damage... which is not a thing you want.

You wouldn't be able to apply it to levelling or anything MSQ related because those are required for all players to do the story and SE would never make it harder for weaker players to get help clearing the MSQ without also making the MSQ easier, and it's pretty clear the playerbase doesn't want that given the opposition to people asking for Shinryu nerfs at the time. That means you're talking Expert, basically, and is it really worth the effort for that and the queue time increase it'd bring?

I also tend to think it's going to promote an echo chamber effect. Gold players only pairing up with other gold players will effectively only see themselves and lose all perspective on what people who aren't at their level are capable of doing. Bronze players wouldn't see anyone better and would get the impression that both the game is a lot harder than it has to be and lose access to people who could both show them it can be done better and offer help to do it (although how often that actually happens is somewhat questionable).

IMO, it doesn't seem worth it. Top tier players need the occasional reminder that not everyone is them and newer players need to be exposed to people who know what they're doing rather than just each other. Then consider this would take development resources away from something else, as well as ongoing testing and maintenance requirements. Code isn't free.