Why is my Big Sur machine so SLOW?

This seems to be a follow on about my phantom HD that was fixed a while back.

What is happening is that about a week after the HD fix my machine suddenly reverted as if that phantom drive was still being written. The second thing I noticed is that the machine seems to be accessing my drive almost continuously instead of 'checking' for connectivity once in a while. If memory serves me correctly, back before Big Sur the lights would flash occasionally but would only rapidly flash/chase light path when data was being written to the HD.

This is a Western Digital Net Book 4T with the huge oval light path that has barely scratched the surface of its capability. It is connected via Firewire.

I just wonder if there is still a hidden file that is being written to. However that still does not answer about the constant light, it continuously dims and brightens but remain in place on the light bar. The only time I have noticed the lights to be 'normal' is when I access either one of the HD icons.

Let's hold on to this one for a while as my HD suddenly started acting 'normal'.