Mac Studio system data using 1.75 TB of storage

If you've automatic Time Machine backups enabled, but do not keep a backup drive connected to your Mac all the time, then MacOS creates and keeps a number of Time Machine snapshots on the drive as part of the backup process.  TM snapshots can occupy a significant amount of drive space. You can disable the creation of these many TM snapshots by setting TM to backup manually rather than automatically at intervals.

About Time Machine local snapshots - Apple Support

You can view and manage these in Disk Utility or in the Terminal app.

View APFS Snapshots in Disk Utility on Mac - Apple Support 

Stefk1972 wrote:

I've done everything that the article states, as well as starting up in Safe Mode & NOTHING works.

That article list several small utilities, any of which can be used to Find the largest file. When your Mac fills up in this way, finding out WHAT is filling up its drive space is essential to resolving the problem.

The other item that can cause drive filling up is Time Machine snapshots. as D.I. Johnson described in detail. When you have not connected your External Backup Drive often enough, it can fill with Time Machine backup data.

the first thing you should do is completely remove CleanMyMac, and never install it again.

once that is done use this article for more insight:

How to free up ‘System Data’ and other st… - Apple Community

Stefk1972 wrote:

Can you explain why Cleanmymac is bad / should be removed?

Besides the excellent explanation by @Grant, other reasons to avoid CMM and other anti-virus apps, cleaning/optimizer apps, and third party security software is because they usually cause more problems than they solve since they operate at a very low level within the OS where they intentionally interfere with the normal operation of macOS & can cause the most damage/disruption. Plus they impact system performance to such an extent that people cannot even use their computer.

I think everyone should read the following article which has tips for keeping your system running safely & smoothly....while written with Apple in mind, I think most of those tips apply equally well to Windows user as well these days.

Effective defenses against malware and other threats - Apple Community

my system data was 1.76tb before I downloaded that app.

Storage on macOS is very complicated. The APFS backup snapshots already mentioned are just one aspect. Another longtime respected & knowledgable forum contributor has told us there are other things which may increase the size of the System Data (don't recall the specific details). However, I think iCloud file syncing & optimized storage play a part as well.

The trick is to purchase a Mac with sufficient built-in storage for your needs with some extra breathing room for growth and keeping 100GB Free at all times.....how much extra storage above what you know you need right now depends on how you use the computer & its workloads. You should consider always having at least 100GB of Free storage space even for light workloads, but never go below 20% of the drive's capacity. Ignore the "Available" storage value shown everywhere in macOS since it is very misleading and is not synonymous with Free. The Free space value is the only accurate value & is the most important one, but it is only explicitly shown in Disk Utility or the System Profiler although it can be calculated from the "Get Info" of the volume:

Free space = Available space - Purgeable space

Even the Used storage value can be misleading under certain conditions....like I said, storage on an APFS volume and macOS is very complicated these days.

Some people will store their largest items on external media so they can get by with a slightly smaller internal SSD, but the internal SSD should still be sized so you can do your main projects on the internal SSD and only store the finished projects on external media.

Just make sure to always have frequent & regular backups of your computer and all external media (including the cloud) which contains important & unique data. There are a lot more new ways to permanently lose access to the data stored on the internal SSD of the recent Macs due to all of the hardware, software, and security changes.

If after following all the usual suggestions and no help then you would need to boot into recovery, erase the drive then reinstall the OS and migrate your files back. This usually lowers the system data number by quite a bit.

<< Can you explain why Cleanmymac is bad / should be removed? >>

Your extremely well-crafted Mac does not accumulate random filth that can benefit from any third-party software to help remove it.

Caches are created to speed up your Mac. Caches hold temporary items that might be needed again soon, so that those items do not need to be fetched again, causing delays. Emptying caches SLOWS your Mac, but if you wish to remove caches, the Best Practice is to do a Restart, not run a third-party app.

CleanMy Mac has no special knowledge of what should be removed in removing apps. It has been known to attempt to remove vital parts of MacOS itself, assuming they were part of a package, and fails to respect shared items that are in use by apps in addition to the app you are trying to remove. It just guesses.

CleanMyMac has been implicated in cases where it was invoked and the Mac it was running on wh=ere so damaged by it, that a complete MacOS re-install was required afterward. it has such a bad reputation here that senior contributors refer to it as "BrickMy Mac". CleanMyMac is junk.