Having issues with fsck in single user mode saying disk is mounted

thespiral wrote:

Is there a workaround for this issue?

Internet Recovery...

External bootable installer...

you have access to Terminal and or a DiskUtility.

ref:

— Recovery (both M1 and Intel) — How to reinstall macOS - Apple Support

—How to repair a Mac disk with Disk Utility

How to repair a Mac disk with Disk Utility - Apple Support

Boot into Internet Recovery (Option Command R) and from the dropdown menu: Utilities>  Disk Utility> run the First Aid on your Macintosh HD (and the "Macintosh HD-Data" volume as well if Catalina/Big Sur/Monterey/Ventura) If errors are found and repaired, run again until no errors reported.

Disk Utility>View>Show All Devices The best sequence is —

Volume level

Container level

Parent drive

—Create a bootable installer for macOS - Apple Support