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.
Spider-Man once single-handedly humiliated the X-Men all by himself without breaking a sweat.
Power has nothing to do with being a street hero. Spider-Man is your friendly neighbourhood Spider-Man because he wants to, and because someone has to be.
Same with Luke Cage and Daredevil. All three have been members of the Avengers. They mostly stick to the streets because they’re needed there, and it’s where they feel comfortable.