Things not working after strip & reinstall

Sorry for not replying earlier.

Having several rotating hard drives can cause slowdowns when opening and saving files, as they all have to spin up. Do you need to have them all connected at the same time?

In terms of software, there are several extensions and daemons running, but the overall system load does not appear to be high.

MalwareBytes is a respectable program, but you don't need to have it running all the time in the background.

About the use of stuff like NordVPN and other VPN "providers" in general, unless it is used as instructed by employer or school to access their network, see: Public VPN are anything but private

This may not be causing a noticeable slowdown, but you are providing an external entity with all your unencrypted data. Do you trust them?

Oh wait... I just saw a lot of "PerfPowerServices" crashes (16 as per the report).

This suggests to me that one of your drives may be failing.

Make sure to have good backups.

You can run Disk Utility first aid on the drives - but know that it finding no errors is no guarantee that the drives are fine.

I would disconnect all external drives, test your mac like this for a while.

Then gradually connect the drives, and test each time to see if there is an impact.

We have no idea what you have installed, many different things could be causing problems,

foremost of them "antivirus" and "cleaners".

Please run Etrecheck and post its full report here. Use the "additional text" button and paste the report into the text box.

To check the health of the hard drive run DriveDx and post the complete text report here using the "Additional Text" icon which looks like a piece of paper. With the Fusion Drive setup it will hide issues of the internal hard drive.

If you want to check the health of the external drives, then you will need to allow DriveDx to install a special USB driver in order to attempt to check the health of the external drives. Even with the special USB driver, some USB adapters, docks, enclosures, drives won't allow the necessary communication to access the drive's health information.

FYI, SSDs are hard to assess so "Warning" or "Failing" notices in reference to an SSD does not always mean the SSD is bad...a manual assessment & interpretation of the health report is necessary. Usually any "Warning" or "Failing" notices in regards to a Hard Drive means the drive should be replaced.

Make sure you install the latest updates of the Mac OS and try to restart and clear cache data