PSA: Riot wants you to have a shitty gameplay experience.
Here's the gist- children and young users buy more RP, per account, because they've got less impulse control and seek instant gratification. By encouraging behavior that causes chat 'toxicity' (gameplay toxicity, such as feeding, griefing, and "AFK" farming) Riot can ban large swathes of players simply for having a human reaction to someone intentionally ruining what should be a fun experience. The more they ban, the better their discipline statistics look to concerned parents, who then become more likely to reward their child's investment in the game buy purchasing in-game goods for them- until that child is banned by the system at some point, having made a habit of spending RP. Too ashamed to admit to their 'misbehavior', they lie to their parents for the RP to rebuild their lost collection- and the cycle continues. Riot's end goal is to have a 20% troll rate, give or take, so that every game has at least 2 players fostering 'toxicity' through 'undetectable' in-game actions.