I take a harder view on the usages of " CleanMyMac " aka BrickMyMac “
CleanMyMac
New macOS Malware "Cthulhu Stealer" Targets Apple Users' Data
Un-Like Microsoft Windows, which does have “ Disk Cleanup “ and “ Defrag “ as part of their Operating System
Apple does not nor are they required.
Certain Applications maybe available on the Apple Apps Store, like CleanMyMac.
This only means the Developer is prepared to pay Apple a percentage on each sale.
What the Application may do to the computer is up to the User to check this out before purchase
Once this type of software are installed and embedded into the computer " CleanMyMac "
Start Over from Scratch
Heavy Handed - Yes ?
Effective in removing CleanMyMac - Yes
For Apple Silicon computer >> Use Disk Utility to erase a Mac with Apple silicon.
For Apple Intel computers >> Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS
Always make a Time Machine Backup before proceeding
If going this route - I suggest Not using Startup Assist to migrate everything back.
This will probably Re-Introduce ( BrickMyMac ) back into the Operating System