Marvel’s Luke Cage has superhuman strength and bulletproof, unbreakable skin, and that’s way too overpowered to be a “street-level” hero. What makes characters like Spider-Man and Daredevil “fun” is the fact that they are vigilantes who can be hurt; they can be shot or stabbed, and their friends worry about them because they aren’t indestructible. But when you have a character that’s indestructible, then all that danger goes away. Also normal thugs aren’t a threat to you.
When people say “street-level hero”, what they typically mean is a hero who doesn’t have strong enough powers to be in the big leagues, think “fighting crime” rather than “fighting alien invaders/gods/interdimensional beings”
That explains the confusion on my end. Appreciated!