I enjoy doing duels as it is one of my favorite games to play. However, I find that often I am battling people who are way less skilled than me (typically stone) that make the game boring as it is easy. I propose that an extra mode to duels is added where players with any rank can play against other players with ranks using the same kits offered normally. Or it could be organized by level, so everyone level 30+ or so can participate in ranked duels.
I do agree that it might get boring if you win everything.
But however keep in mind that Duels are part of the "Daily Challenges".
Adding this, and possible not winning anymore would kill the purpose.
Then you could say "You could either go to the "Ranked" part, or the "Normal" part!"
Well yes, but as far as I know, the Duels community isn't that big.
There's currently 27 people playing it, and splitting up 27 people doesn't sound like a great idea, tho you only need 2 people to start.
Anyways, by rank: totally a no from me, by level: a small yes.
But then again, not all high-levels are as good, and they might never win again.