What is “system storage”?
What is system storage and why can’t I delete it from my iPhone 8 Plus?
iPhone 8 Plus, iOS 13
How much space is your 'system' storage taking up? It's perfectly normal for this to be ~ 6 or 7 GB. If that's what you are seeing, you cannot delete that. Much of that is iOS itself.. so if you somehow deleted that, you wouldn't have a functioning phone.