Windows 10 shows 100+ GB in “System & Reserved” but MFT, shadow copies and WinSxS are small – where is the space used?

I am trying to understand why Windows 10 reports over 100 GB used under "System & Reserved", but I cannot find what exactly occupies that space.

System details:

• Windows 10 Pro 22H2
• 32 GB RAM
• System drive C: ~292 GB (NTFS)

What I have already checked:

1. DISM cleanup: DISM /Online /Cleanup-Image /StartComponentCleanup → Completed successfully
2. Shadow copies: vssadmin list shadows vssadmin list shadowstorage → Only ~121 MB used
3. NTFS info: fsutil fsinfo ntfsinfo C: → MFT size: 128 KB → Total allocated clusters: ~73.8 GB
4. MFT allocation report: fsutil volume allocationreport C: → Large number of entries with File ID 0x000100000000001f (MFT)

However, according to Windows Storage settings, "System & Reserved" uses over 100 GB.

Questions:

• What exactly is included in "System & Reserved" category in Windows 10?
• Can NTFS reserved space or MFT zone be incorrectly reported there?
• Could pagefile.sys, hiberfil.sys or Windows Update reserved storage account for such a large discrepancy?
• Is there a way to precisely determine what occupies this space?

I am comfortable using PowerShell and low-level disk tools, so technical explanations are welcome.