[2020] The reason Jax, Vladimir, Kassadin, Yuumi, etc. have such disproportionate views of their strength compared to their actual winrate/competitive power is because most popular champions are early game champions and people don't realize they got carried by that fact.

Game 1 Renekton: "man i completely smashed the enemy vlad... dude was so diffed lol, only reason im in this elo is because of bad teammates"

Game 2 Zoe: "/all is mid open? XD" enemy vlad prob boosted idk how this guys in this elo, outcsing him while outroaming him too"

Game 3 Thresh: "enemy team said i was scripting LOL... so ez to dodge hooks"

People who main these champions assume that because they win lane most games, it means they're a better player than others in their elo. To everyone who actually plays other champions in the lane, it's obvious that these champions have almost no counterplay early and just smash almost every matchup they're in. But when the enemy laner is able to comfortably scale up and allow themselves to be at a deficit then carry later on in the game because the Early Game God was unable to close the game out, they cry. Which is why you have

Game 4: "balance team??? HELLO??? jax and yuumi literally 2v5ing our team... just farm until 40 and win every game, what can u do against this?? no counterplay, won lane but lost game"

Discuss. We haven't been in an actual "lategame meta" in over 5 years. Last time that teams genuinely played for late was in Season 2.

Sometimes people will make the argument "but even if i try to snowball my lane, what if -other- players on my team don't follow my calls and we lose?" Yeah, that's not exclusive to you. If you play lategame champions, you will get the opposite problem: Teams not following defensive calls, dying, and snowballing the game naturally or just ragequitting.

EDIT: Since this has been mentioned in a few comments already ("games go longer in low elo matches so lategame champions should be better, right?), I'll address this question in the thread body. Most lategame champions have a lower winrate in lower elos because teams give up faster in low elo and don't know how to play to scale.