Last Summer, a new Endorsement System was introduced in Overwatch. It was made to discourage toxicity by rewarding good behavior, rather than just punishing bad.
The way it worked was that it enabled players to rate others who are good teammates. In a matter of weeks, the system worked. Since then, the system has continued to bring in positive results. During a GDC talk, research scientist Natasha Miller reported that it was due to the endorsement "levels" and randomized loot drops, that there was a 40% reduction in matches with disruptive behavior, with between 50 and 70 percent of players handing out endorsements.
It also helped that the system called for consistency. If the player was not consistent in their endorsements, they weren't going to get any endorsements and their level would slip. For those who wanted to get back to their level and keep going, they had a chance to redeem themselves. On the plus side, those who reach higher levels of the Endorsement System are grouped with other highly-endorsed players during matchmaking.
Further refinement will be done on the system, according to Miller.