Did you use a specialized utility, similar to a well respected CrystalDiskMark?
Please share screenshots if you did, I am sure some people here would be interested to learn.

It's a common knowledge that external USB drives are less stable performers... in most cases.
You didn't answer this: does your computer has USB 3.2 Gen 2 ports?

P.S. To me, it's no brainer. If my system has enough resources, why would I want something attached to computer that I don't need?