How to clear system data on MacBook Air M1 ?

Hey y'all,

I've had my M1 Air mac for about 3 years and have managed to fill up my storage disk. I have the base M1 air with the 8gb ram and 250GB storage. I had a look and saw that 20GBs of macOS data and 70GB of System Data. i was just wondering if there are any ways to clear the system data or if there are any ways I could prevent more system data stacking up. I asked IT support but they said the best way to clear it was to wipe the computer and re-install the OS but the last time i did that i still had quite a few GBs of System data remaining.

Thanks

[Re-Titled by Moderator]