You're not playing many ranked rounds, but this is not the only asset valid in your tiering career.
Your 73 RRs stand in contrast to the number required by this path: a minimum of 100 to even become a TM (40 as a Master, 25 as a TP and another 35 before that). You'd have to add 50 RRs as a TM...
I'm guessing that you play quite a few "mobile" games like H2H and coin rooms - your diligence and success there will widely contribute to your rise, and the average is out of the equation.
You just haven't hit it yet, and we can't tell what's missing...
Have fun!