@Garlor;
You are correct, true HDR should be comprised of several (3+) bracketted images.  But, as you also point out....it is not always possible to achieve this because of movement.
Using a single image to create an HDR has been called "pseudo" HDR...it is not ideal, but it does provide some improvement.

Regardless, there is still much flexibility when working with RAW images...you don't have to go the HDR route to benefit.

In youth, we learn....with age, we understand.