Depending on your success ( hopefully so ) visa vie Snapshots build ups was the root cause of System Data growing to large
If this has not been resolved ?
Reducing System/Volume/Data is a common question.
1 - System data taking too much in MacOS Sono… - Apple Community
2 - Time Machine Local Snapshot won't delete - Apple Community
3 - Over 60% storage blocked by System Data - Apple Community
How to free up ‘System Data’ and other storage on your Mac from a fellow colleague @ neuroanatomist
Use another application to see where space is being used Storeograph on the Apple Apps Store
Suggest getting an External SSD Drive and start moving your Pictures, Videos, Music and any other large files you have control over, OFF the Internal drive and Onto the External
Understanding iCloud Drive from a well written User Tip from @ Richard.Taylor
There are two effective ways to remedy this issue:
1. Quick Fix Actions:
For Apple Silicon computers, use Disk Utility to erase a Mac.
For Apple Intel computers, use Disk Utility to erase an Intel-based Mac, then reinstall macOS.
Always make a Time Machine backup before proceeding.
Migrate only the user account, not the entire system.
Reinstall only the necessary applications from the Apple App Store or directly from the developers.