lol. i can't remember ever feeling real terror from any of the villains in dbz. but i damn sure remember the terror i felt when tao entered the show. i think he was the first villain that outclassed goku in every single way. and jfc, remember his transportation? it was a kittening pillar! it doesn't get more badass than that.

It's because arrogance was their chief calling card. It was their dominant personality trait, and dominant by a large margin. There was really no differentiation between the villains, something Naruto suffered from as well.
In Naruto, I only actually felt danger from two villains, Obito and Pain, and Pain less so when it was revealed that he was just an intermediary body between Nagato and Naruto, so it lacked a solid connection. Madara had no personal connection with Naruto, so he was a trash villain. As soon as he appeared, I was knew he was strong but I also knew he was going to eat kitten, so he never really concerned me. The same with DBZ. In terms of villains, OP and Bleach do a much better job for a couple reasons:
The backstories are better.
There's no inclination on the part of the villain to turn good out of nowhere.
Their character traits extend past arrogance bordering idiocy.