My belief for QP is that it doesn’t require voice chat, it’s all about reading the play from your own perspective and acting accordingly. I find it has helped me understand the game and its roles better, as well as getting a better understanding on what the average player will do without full coordination and helps me to assess situations better and faster.
While you should still try to win in QP, to me, it’s more for self-improvement from a discipline and positioning perspective. Communication and shot-calling are best learned through comp,with at least one friend and/or with players who are willing to accept your leadership or teaching you how to point out things and command as fast and polite as possible. It also helps if you’re having fun with taking the lead, as well as everyone around you.