iPhone 13 keeps showing error “Unable to Install Update” starting 07/11/2023. Even though mine is the latest version plus latest security response update.

I went to Apple Store today but was told to reinstall. This is nonsense - how could they not able to find out the exact cause of the error? I’m a software developer and I also do customer support and I feel shameful to tell my customer to fix an issue by starting over. The support guys in the store have very limited way to look deeper into the problem- almost same knowledge level as us non-Apple employee.