"If you're not a good shot today, don't worry. There are other ways to be useful."  - Sova
I'm sorry Sova, but I don't think this is the case.

I'm feeling sometimes not useful when playing a support agent when K/D is the most important thing for the ranked system.
If my team is doing well playing offensely, I see that i don't have a lot of kills so (because of the way ranked system works) I start thinking : "Well, I should go try and get some kills"
But its not easy to get kills with a supportive character (especially those that aren't that good offensely like Cypher). Sure I can kill one or two before I die, but I can never do as good as the Reyna/Raze on my team.

So why not give "points" for using skills on the game. Similar to how it works on Rainbow Six Siege, when a gadget is activated you win points for it, and those points matter in your position at the and of the game.
It's easy to kill 3 in a game where the other team is not doing so well if you are a Reyna or a character with lots of heals (and maybe it's easy with a bazooka too) So why not implement a system like this?

And please don't get me wrong, when I say "points for using skills" I mean for everyone.

Reyna used the eye? Get some points

Sova used the scanner arrow, Get some points. Found someone? a little more points then

Cypher used cam to tag someone? Get some points, Caught one in a trapwire or someone passed through the cage? Get some points.

Raze annihilated a dude with a Bazooka? Get some points as well.

This way maybe if you are playing supportly you can at least get a good "classification" and earn the elo you deserved. Of course the dude that killed more still gets more elo, but as Sova said, with this system, if you aren't in a good shot you can be useful, and be rewarded for being so.

Sorry for any misspeling, engllish is not my primary language.