Elizabeth Warren is one hell of a politician, and i think she's right. The subscription-cut is too high. It's in Apple's best interest to fix that.
It may be too high, doesn't mean people have to use it though. You don't go around stores and telling them their products is too expensive and they should lower their prices. And you also do not lower your fees just because some politician who will say anything to become a VP said your fees are too high.