Actually looks more like plat is top 15%, going by all servers anyway.
I think a good rank is gold. You have a grasp on the game and can hold your own against over 50% of the playerbase.
Now high elo is a whole different animal. I'll say this here and now, I think high elo players in masters aren't that good. A lot of these people try smurfing in low elo and they play as if they're in challenger. You're not. Something I absolutely hate about playing bot lane; I have to rely on a team mate in lane. High elo players play as if the team mate knows what to do and how to rotate and good zoning/engage/disengage/watch the map.
Of course there are people who are professional smurfs, they make a career off of climbing the ranks. Tyler1 could be considered one because of all his bans and climbing on new accounts. Rat IRL, Dekar173, ScrubNoob, TFBlade, Damir you get the idea. These people know how to play in each elo. They know in iron to gold they can solo carry and not rely on their teams. In plat it's possible but not as easy because now you have people who know how to use their lead. Once they get to diamond they flame so much because they expect challenger but they're in diamond.
Yassuo once said this about (I think) Damir himself, that he can't climb in low elo the way Damir can. Now of course that's not to say Yassuo, Voyboy, Dyrus, Imaqtpie, etc. would be stuck in iron 4, they can easily climb to diamond. But they've learned to solo carry without relying on people, because that's how they solo queue, and former pro players can switch their playstyle between "my team who I live with" and "random college kid streaming without a shirt on in d1", but some people know how to do it a lot better. I think they've just been in this same skill range for so long that they're playing a different game. Everyone knows where the jungler is, where the roaming mid laner is, where the wards are, it's not the same game. In gold/plat I can sweep and find a ward at dragon, a ward at the river bush, and a ward in the bush opposite side blue buff back wall, or I can find it sitting in the middle of bot lane in a terrible spot, even found some NEXT TO a bush. In challenger/gm? Same fucking spots.
inb4 "then get challenger" or "1v1 them". No. I really don't have the low blood pressure to play this game religiously and become a high rank, nor am I that good. Plus high elo in most games is boring. Got to one of the top ranks in Wizard101 back in like 2010, got real boring. Same decks, same armor, same meta. Same with high ranks in Dead by Daylight, Overwatch, League of Legends, and frankly I don't want to deal with some of the fuckery that goes on up there. I don't want target inting because Chase Shaco is on my team, I don't want to deal with Tarzaned going AFK because Dekar called him a fetal alcohol baby on Twitter, I don't want PornStarZilean playing Nunu because his father didn't love him. Everyone imagines playing with imaqtpie and knowing everyone and they know you, but that's really rare unless it's a slow day.
TL;DR - Gold is good, high elo (above diamond 1) is overrated. Enjoy your elo if you're mid gold, it's pretty close to paradise. Most people don't have an ego, everyone understands they're in gold together. Nobody is stressed about getting gold 4 for the season skin. Plat is where the toxic egomaniacs go.