My anecdotal impression of the meta as a high Plat - low Diamond

I recently made a hero tier list and was wondering if anyone could tell me how close or off I was. I’m not certain about some of the placements so I wanted to hear everyone’s thoughts. I think I have a reasonably sound idea of how the game works but I’m not close to being an expert. I’d like to understand everyone’s place in the meta a bit more. Here’s what I ended up with:

S Tier: Meta defining picks
Orisa, Hanzo, Mei, Baptiste

A Tier: Strong meta picks with consistent and applicable value, good with meta pairings
Reinhardt, <- (considering moving to S) Sigma, Zarya, Ashe, Doomfist, McCree, Reaper, Lucio, Zenyatta

B Tier: Still strong picks in/against the right comp when played well, but might be map dependent or mildly outclassed
Winston, Wrecking Ball, Widowmaker, Ana, Brigitte, Mercy, Moira

C Tier: Situational, but effective when they are needed and in the right hands
D.Va, Roadhog, Junkrat, Pharah, Soldier: 76, Torbjorn, Tracer <- (really unsure about her?)

Meme Tier: Victims of power creep, highly situational, hard to get consistent value from, or entire team strategy has to revolve around them
Bastion, Genji, Sombra, Symmetra