Windows 11 Error: UNMOUNTABLE_BOOT_VOLUME (0xED)

Good that you already copied your files off. UNMOUNTABLE_BOOT_VOLUME means Windows cannot read the system drive at startup, which is usually file system damage after an improper shutdown or restart, and sometimes a failing drive. You can try to repair it without formatting. In the Command Prompt you already have open (from Recovery or Safe Mode), do these in order:

• First find the real Windows drive letter, because in recovery it is often D: instead of C:. Type dir D:\ and look for the Windows and Users folders. Use that letter below.
• Check the drive for errors: chkdsk D: /f /r and press Enter (answer Y if it asks). This can take an hour or more on a large drive. Let it finish and do not turn the computer off.
• Repair system files: sfc /scannow /offbootdir=D:\ /offwindir=D:\Windows
• Repair the boot files: bootrec /scanos, then bootrec /rebuildbcd. If it says access denied or finds nothing, type bcdboot D:\Windows and restart.
• Restart and see if Windows loads.

If chkdsk reports a lot of bad sectors, or it stops or hangs, the drive itself is probably failing. In that case keep your files copied, and plan to replace the drive instead of repairing it. If the screen asks for a BitLocker recovery key at any point, you will need that key before any repair will work. You can find it by signing in to your Microsoft account on another device.