Plat 3 player, played all my placements in plat-diamond lobbies, go 2-3 match MVP'ing both wins (one with 30 kills), placed silver 2. Silver 2? Like, what even?

I'm someone who always tries to be kind to both teammates and enemies, stuff like glhf, ggwp complimenting the enemies for hitting amazing shots when they kill me and trying my best to boost my teams moral and keep us all happy. Quite often...