Hello, thank you for reaching out to the Microsoft Community. I am here to help and provide assistance with any questions or concerns you may have.
From a technical standpoint, your observation is accurate. Essentially, any process utilizing the HDD should generate some form of activity.
In this case, particularly with Quick Scans, the focus tends to be on common malware hiding spots, rather than extensively reading every sector of the hard drive. As a result, the disk activity might not be as pronounced.
To dig deeper into disk activity details, you can open the Resource Monitor (resmon.exe) and navigate to the Disk tab. This should provide a more specific insight into which files or sectors are being accessed.