What can we conclude from the average level of champion mains?

https://www.leagueofgraphs.com/champions/main-stats

I'm not sure which is the best conclusion of the data.

1. The champions are easier to climb with when you are experienced on them, so the average rank is higher.
2. They are more difficult to do well with, so lower ranked players tend to avoid them or don't do well with them.
3. The champions are only good at higher ranks with better teammates, so only higher ranked players tend to play them.
4. Simple popularity differences. Maybe younger or lower skilled players are drawn to certain aesthetic qualities, rather than power and abilities being what draws people to them, that make champions popular at lower ranks.
5. The lower ranked champions are so popular across such a broad spectrum that it skews the rank to be lower.
6. The sample size of high ranked mains is too small, so it skews the results.

Then you also have the reverse to consider - Why is someone like Miss Fortune and Lux the lowest average rank despite a decent main rate?

Janna would seem to to prove that #1 is the best answer. She is #3 in main rate. She's not difficult. Yet her winrate is high in both low and high elo. Her kit is easy enough to execute, and impactful enough, that it can turn the tide of low elo clown fiesta ARAM fights. But it's also powerful and nuanced enough that it can turn the tide of high elo skirmishes and teamfights. The only potential skewing factor here might be that low rank players are not drawn to her aesthetics, or reject support in general as a main role.

Ezreal is also one of the higher ranked ones despite being #1 main rate, although in his case I'm not sure why. I don't like Ez and don't consider him particularly good. But he's definitely popular among low ranked players and players across a broad spectrum, yet still is high ranked, so that would go against the idea that low elo popularity skews the results. Ez has the largest overall play rate by far. It's not even close. Maybe a lot of people dabble in him but just don't main him.

I actually tend to see Jhin a whole lot more in silver elo than Ez. Ez is not common. I see Jhin as the go-to newb adc because they are drawn to wanting to be a sniper character and don't give a damn about what their role actually is suppose to be. They just want to get that sweet long range ultimate kill shot at some point in the game and won't even get into auto attack range half the time. He's the Yasuo of ADCs. Everyone wants to play him for his style but they are usually not that good on him.

Camille and Riven are also a pretty high main rate to go along with their rank, but not necessarily easy to play, so it's harder to analyze what's going on with them.