Why are there no write protect switches on any of the USB flash drive as on floppies and SD cards? USB flash drives are sometimes needed to reinstall a clean copy of the operating system if the hard drive becomes unbootable. If I buy a retail copy of Windows 10 on a USB flash drive, that flash drive is permanently write protected by Microsoft using special mass production tools to protect the preloaded Windows 10 installation files and they are often outdated quickly. If the flash drive created with the Windows 10 Media Creation Tool becomes corrrupted and the hard drive becomes unbootable, I would need to have access to another working PC in order to redownload Windows 10 using the media creation tool as it can only be done on a working computer with an OS already installed and connected to the internet. Windows 8.1 or earlier was shipped on DVD which was read only but must be handled carefully as they can be scratched.
The best write protection, for USB drives and CDs, is to have backup copies of the devices.