Ok, for you to say,

Nationality, ethnicity, and race are all different things though in common language often spoken interchangeably.

That doesn't make it correct. Yes, this is Medium. Not Twitter, Facebook, Snapchat or 4chan. I expect better here.

“Words are weapons, sharper than knives.”

It is the finer distinctions in definitions that provide clarity of meaning.

If you knew the difference why choose the less accurate word?

TEK