HWTech wrote:
No, do not delete it. Beginning with macOS 10.15, macOS now uses multiple APFS volumes....a read-only system volume and a read+write data volume. Each version of macOS since 10.15 has changed slightly and Apple uses slightly different "tricks" to link the various volumes together and places the mount points at slightly different locations depending on the version of macOS. Keep in mind the mount point is within a "System" folder. You usually don't want to touch anything located within a folder named "System" since it implies the contents belong to macOS.
About the read-only system volume in macOS Catalina - Apple Support
Seconded.
OP, the "Macintosh HD" volume that appears in /System/Volumes is actually your Data volume. It is where all of your apps, settings and files are stored.
For context, in macOS Catalina and later, your Mac uses two important volumes: the read-only System volume (Macintosh HD, the root volume), and the writeable Data volume (Macintosh HD - Data, mounted at /System/Volumes/Data). These two volumes are linked together in a volume group, and firmlinks (bi-directional wormholes) intertwine the two volumes together.
When you use the Finder, it presents a unified view of the two volumes, and shows their merged contents. If you want to see a good example of the Finder's magic at work, check the system-wide Applications folder. It contains both the preinstalled apps (located in /System/Applications) and your third-party apps (located in /System/Volumes/Data/Applications).