Ranked missions

Riot pushing players to play ranked because esports ready am I right... No infact this game is anything but esports ready because of how toxic most of its player base it...3-4 years ago this game was more about having fun trying new things making up shit like flash insect lee or breaking the game rules and just having fun now it's nothing but meta champs destroy every game people rage int and have their head up their ass...two games prior to season 8 starting I was having nothing but fun playing random shouldn't work in certain lanes champions like kha xiz top where I was destroying but normal Q was hell so I was playing in ranked Q because nobody who cares to much plays ranked during preseason now that season 8 has started the Q is nothing but toxic players who blame other players or just plain have a shit attitude towards other players specially in promo's...instead of promoting hey play our game have fun they are promoting hey play these specific Q's which players are over judgemental about because you know that one symbol from this weird ranking system that demotes you every new season because you know reasons instead of everyone starting on a blank slate for a new season like most other games, this one rules into account your prior season rank because you know nothing changes right before a season starts right?! making everyone's skills change like idk say a complete jungle rework or a rune and champ over hall or say like 3 new champions in the span of a season one who shows up like right before the end of the season and during a massive gameplay rework....Nah that makes to much sense lets do this with some weird illogical formula that even if you win every game 10/10 in your promos you still get shot from silver 1 to bronze 1 because you know "leaderboard shifts" the fuck does that even mean how does a leaderboard change from one season to the next in a way that affects the ranks of what should be a completely new blank slate season...I just don't understand it. [sg-lux-2] Could someone from riot explain how this strange system works in detail because all I seem to get from it is nonsense reasoning?