Since Season 6 started yesterday, how did your placement matches go? Placement Matches should be a lot more accurate now, which imo, they are indeed more accurate.
My main got placed in Platinum (2555 SR) after climbing from Gold to Plat last season. On my main I mainly just flex and pick whatever is needed. My smurf got placed in Diamond (3294) playing DPS only (99% Genji)
It's kinda frustrating that my smurf is a lot higher than my main, but meh.