How to clear system data in iphone?

My iphone xr got huge system data - 37g now. My total memory is 64g. It is almost out of memory. I have to keep removing apps. I don't have much to remove now. I tried every way I can find online to clear this stupid system data except reset my iphone. Nothing works. My ios is 15.5. Anybody has same issue? How do you fix it?