Over 400gb System Data

[TripleYoThreat]

Hey all! I tried what the results show here on MacRumors and otherwise on Google

1. I removed the Document Revisions folder.
2. I checked Time Machine Backups
3. I also checked the Photos app as per this similar thread here

All no dice. I did an NVRAM reset, no go. this is an iMac Pro 2017.
What could be going on here? Did a sudo omnidisksweeper as recommended on the Apple forums, n this is all I got

What gives? Any ideas? Really aiming to avoid the wipe and reinstall. And even then, how can I prevent this in the future? Seems important to find the cause (besides curiosity) to actually tame it in the future

Thanks in advance!

 

[Fishrrman]

Download DiskWave from here:

DiskWave Homepage

It's small in size and free.

Open DiskWave and go to the preferences.
Put a checkmark in "show invisible files".
Close preferences.

The DiskWave window shows you all your volumes and drives in plain English (no ridiculous graphical formats).
Click on any item "on the left". Give DW a moment to examine things.
Now, you'll see what's ON the volume, listed in order of "largest to smallest".
You can easily locate what's eating up your space.