thats because in football, first they have about six million statistics about players while in LCS they have like 3, and second because almost all ball games including football and soccer are actually very straight forward games as everything you do gives instant feedback, so the statistics they have are actually somewhat a resumee of their play.
the difference to league of legends, aside from the LCS not really having super tons of statistics or at least not publishing them all, and league being a very very very very very much more complex game, is the coming off those statistics. this guy has a good KDA cool, but where does it come from?
sure, christiano ronaldo scores tons of goals in madrid but on the national team he doesnt shine. why not? because he gets enabled by his really good madrid teammates to do his great plays.
this means, its not 100% his own achievement.
its the same in league of legends, but since its so complex here and also KDA in league isnt equal to goals in soccer, the statistics have entirely different meaning. its not like cool ronadlo won a duel and scored a goal all by himself and now he has +50 movementspeed and increased dribbling for 10 minutes and it snowballs into 6:0.
in league, things can have very hard to calculate long-term effects. rumble takes one bad trade against hecarim and loses 20% HP more than he needed to and loses 15 extra minions over the course of 10 minutes and now there is a teamfight and hecarims team barely win and escape with 100 hp but rumble just missed 200 gold to finish liandrys and now because 15 minutes ago he took this one bad trade that nobody talked about, his team lost the game. even tho its not SOLELY because of that, it couldve changed everything in theory.
and basically almost every single move in the entire game that people make has these long-term effects on certain other situations.
this is how complex delayed effects league has. none of this exists in football or soccer.
so, go ahead, be a noob and celebrate high kda players and praise them for how amazing they carry but still lose because their midlaner sucks.