The Unfair placement of SR system

So I wanted to finish my last 5 placement games so I can be placed in certain SR rating. In those 5 placement games I lost all of them, but 4 out of those 5 games, there was always 1 teammate that would leave the game, so we were left to 5v6. Not only that but I dropped around 200 SR from where I was originally.
So from this what happened, are you telling me, Jeff, that the rest of the people on the team should suffer a huge SR lost because one person left their team to 5v6 and would only get little to no punishment at all?
Not only that, but the community wants to know HOW does the SR system work, so we don’t have to turn into toxic players.

What was your overall placement W/L/D? Did you win all of your first 5?

I know when people leave a non-placement match, they lose 50 SR automatically. I would think it wouldn’t be any less for leaving one of their placements. From my experience, you lose an average of 25 SR for a loss.

See How Competitive Skill Rating Works (Season 10), especially the section on the leaver penalty.

If you do your placements at the beginning of the season, when more serious and consistent players are doing them, they will usually be a better experience.