Forgive me, I thought we were talking about with the follow-through. In this case, I guess it's just as easy if you practice, which most people don't. People do practice the overhand knot though.
So, an overhand knot is likely easier for most people, where a figure-eight would be better for those who practice.
https://www.101knots.com/wp-content/uploads/2016/11/How-to-T...
In fact, I've practiced the figure 8 knot so much, that it takes more effort for me to do an overhand knot these days. Figure 8 is really easy.
Just as the "Granny Knot" is a mistaken square knot / reef knot... the "Overhand Knot" is basically a mistaken figure-8 knot. Just turn the other way, and the knot will be far, far stronger.