I used to like to invite someone based on if they had a medal, and what rank they had. Bronze/Silver or Gold.
This was a true measure of someone’s ability in their role as tank/heal or DPS(DPS required things like interrupting etc).
We need this type of system back on top of the M+ score.
I want faith that people I am inviting can do their role they sign up as.
It could even go a step further, require bronze for a normal dungeon, silver for a heroic dungeon and gold for a mythic dungeon - adding the mythic 0 to a queue system with normal/heroic.