possibility of transferring the system in a USB Hard Disk

[Tim Curtis]

Raspberry Pi has supported Booting from USB drives for a few years now. You just write the image to a USB stick instead of an SDCard. IIRC not all USB sticks are recognized by the Pi.
https://www.raspberrypi.org/documentatio...des/msd.md

The Pi 4 apparently requires an updated firmware to boot from USB device.
https://www.raspberrypi.org/documentatio...torageboot

And there is now an official Raspberry Imager.
https://www.raspberrypi.org/downloads/

Note, I haven't tried the new imager or firmware update on a 4.