A USB drive consists of a chip that creates a bridge between the USB and the flash chip, and the flash chip itself. Sometimes I managed to buy one with an eMMC chip as a flash - these drives work well and do not have setup utilities. However, most USB drives contain a NAND flash as a carrier for reasons of cheapness. Accordingly, the USB bridge chips of such drives have setup utilities. I installed such a utility once, it contains viruses and irreparably damages the USB subsystem (requires a rollback in the form of a system image).
However, in the utility settings, in addition to various parameters for NAND, there is a window for choosing what this flash drive will be. You can choose a USB floppy, USB cdrom.
And so I constantly hear that everyone creates "bootable" disks with some program. Therefore, I decided to write this text to improve understanding of the issue.