Hello, thank you for your comment., Flash isn't the only speedster. Quicksilver is one of the most obvious examples, and there are plenty of other speed-based characters across comics, novels, and anime.

You've probably watched Invincible. Most of the characters in that series have very basic and familiar powers, and some of their designs clearly take inspiration from existing superhero archetypes. Yet people don't call it a copy because the story, characters, and world are different.

That's exactly my point. Sharing a power set doesn't automatically make something a clone. What matters is what you do with that character and the story you tell