Diamond People How did you get there

Okay so this last season i have climbed tremendously from silver 1 to my peak at 100 lp in plat 3, however i seem to be stuck here. So my question to yall Diamonds is, do you play flexible pool of champions at a high level in multiple roles, or do you play 1-2 champions in one role very well and the rest is mediocre? Thanks friends <3