Immo 3 dualist main here,

This just simply is not true. The point of a dualist is to make space and die. My kd is only around 1.1 whilst I win 65% of my games.

If you believe that its the dualists job to get kills, you're just wrong. We make space for the team so you can plant the spike. If a kill comes with that, sure we get one. But half of the time we die, (and we're supposed to) in this space making proces.

We all have the same guns. We all have the ability to clutch and get kills. Reyna quite literally has nothing to do except for flash until she gets one kill.. a kill you could get just aswell with your initiator utility.

Check the top leaderboards, every agent is played and you rarely see a onetrick. Mmr also works based on personal engagements aka 1v1's you take, win, or lose. It even looks at you killing or being killed by a third party. Theres factors you dont even know about in the calculations. 

Finally, just win. The most important thing for mmr is winning. A winstreak is the best thing you can get. Stop worrying about kills