Are placement games even relevant? Ranking Issues?

Hey everyone!

I just made a topic about my situation which I found a bit unfair. Now that my head cooled down, I think I was whining too much! Anyways, a question appeared in my mind. Why do placement games if you know where you're going to end up anyways? We all know Challenger, Master end up in Plat. 1 as Silver ends in Bronze. Why waste time doing placements if you're going to get there? That's 10 games you could have been grinding already. I mean, if you're new to Ranked, it's all good to have placements, but for old accounts, what is the point? 10 games represent a decent amount of time invested.

Thanks for the feedbacks, TimerClock