The Windows media creation tool is designed to upgrade a machine or it can make and ISO disk image or bootable USB stick.
There is no fault tolerance, if there is a problem with the USB stick and you have to start over, expect to have to download it over again. The tool does not retain the files it downloads.
Microsoft clearly has to fix this problem as bandwidth can be expensive.
Given the USB stick has to be updated semiannually there is the chance the USB stick can be damaged unknowingly. This is a very glaring bug that needs to be fixed.
Remember that if you have an older version of Windows on your USB stick, this will not work to fix a broken windows setup. Make sure that when a new version of Windows is delivered that you update your recovery media.