Hi, how big is ur phone storage capacity? If it's 512 GB, it's normal to have ur system occupying 59 GB. For mine, my phone is 256 GB variant, the system is alr occupying 43 GB.
Actually, this system memory helps to keep ur phone running smoothly. Normally, it shouldn't exceed too much. If it exceeds 100 GB, then it will really call for a concern.