system takes up 50 GB of storage
The value that you see listed includes many things we wouldn't consider part of the system. If I do the same on my machine it says System is talking about 130 GB. If I run DaisyDisk on my drive it says System is taking 9.8 GB. You can download DaisyDisk and see what's taking up space. DaisyDisk is not free but they offer a free trial.