I'm not 100% certain but I want to when you send request to randoms, it only sends requests to players similar rank to you, similar to how you can only use random supports of similar level outside of your friends. Meaning you aren't gonna be getting help from high rank players who can easily solo. People who've been actively playing from launch are around 80~90 and those who are cash players are easily 100~110+. And because of this, you only find help requests from other similar ranking players, to prevent things like high ranks sniping kills off low ranks. Friends and unions are the exception.
But like I said, not 100% certain if that's how it works. That'd be my guess why you need so many people to help you.