I'm the one who downvoted and here's my reasoning:
In my opinion 1v1s should be left up to the players, they should never be turned into a game mechanic with rewards. Chatting about unrelated stuff, agreeing to change the rules mid-game, or extending the goal and continuing to play, other people joining in to spectate and then deciding to also 1v1 in the same squad, etc. are all fundamental parts of how 1v1s work right now, that make them feel alive, social and memorable. This actually makes it different (and better) compared to many other games, where people just play for the gameplay, rewards and are incentivized to cheese their way to victory, instead of primarily trying to be nice to their opponent. Your suggestion will in fact make it more boring and repetitive, compared to current unique and unpredictable 1v1s.
The "if you don't like it, don't use it" argument doesn't work, because it depends on other people. And with this suggestion, many people will switch over to the new system, resulting in be less people willing to do 1v1s the old fashion way.
Though I do wish there was an easier way to find people for 1v1s, while what players end up doing next should remain up to them.
Regarding the leaderboards, I don't think there should be one primary publicly visible value for comparing who is better and who is worse either. Who is better "in general" is subjective, and trying to provide a seemingly objective answer to it is wrong (even if devs claim it does not represent "better in general", people will treat it as such regardless, provided there is only one value). If there is such value, even people who otherwise don't want to interact with the this ranking system, will still feel some social pressure to get their leaderboard value up.
A better solution is to have multiple different leaderboards of equal-importance, so that there isn't one primary thing everyone is obsessed over, and as such, no social pressure on people who don't care. In practice though, it may be difficult to achieve as players might assign one of the leaderboards as primary one themselves.
I also think that the account stats tracking update in summer of 2023 had an overall negative impact on the game, as people started to leave matches to also keep their account stats good, or get frustrated when they "ruin" their stats. At least stats are still not public and at least people are not punished for leaving, which are both ways to make the game even more frustrating.