Superheroes come in different flavors or power levels though. From street level heroes (Daredevil, Punisher, Phantom, Green Arrow, Iron Fist etc) through to four colour heroes (Superman, Thor, Wonder Woman, Captain Marvel, the Hulk).
Batman started as a Street level hero, and then progressed to four colour (when he started doing the Power Armor, Bat-attack-helicopter-spaceship-thing and so forth).
Street level heroes are generally superbly trained humans, or low level super-humans with limited powers. You generally dont see them firing beams of energy from their hands, flying, teleporting, throwing around trucks like confetti or whatnot. MCU's Defenders feature 'street level' heroes. These guys fight street crime, and occasionally deal with a threat to their city or community.
Four colour heroes are superhuman and display fantastic abilities, technology and power on a cosmic or near cosmic scale. The MCU Avengers and DC Justice League are examples, and they're fighting cosmic and existential threats to the entire Earth (and indeed the Universe).
In DnD terms, at T1 and early T2 PCs are roughly equal in power to Street level superheroes. A 5th level PC would be a match for Daredevil, Phantom, Punisher etc. By the time the PCs have hit T4 they're sitting at Avengers levels of power and dealing with the same sorts of threats.
When an Illithid armada plane shifts in over Waterdeep, led by an immortal CR30 Elder Brain of the God that predated Ao and bearing 5 linked artifacts of ancient Tharizdun, seeking to uncreate the Universe, it's the 20th level PCs who get the job to stop them.