Since at least 1987 and John Byrne's re-boot Superman has been far from his Silver Age godhood of sneezing and destroying solar systems. He can be brought low by quite a few beings who are near or at his level in terms of power: Darkseid, Lobo, Mongul Black Adam, Shazam, the list goes on. He's vulnerable to magic as well. But <script id="gpt-impl-0.1399824301753036" src="http://partner.googleadservices.com/gpt/pubads_impl_75.js"></script>admittedly his "supremacy" is part of the appeal. Being the original gangsta of OP is kind of his thing, so if you can't get over that it is understandable that the character may leave you cold. But in all seriousness his real power is the same as all the other super heroes, fans just don't want to admit it... PLOT ARMOR. Spidey, Batman, Cap... Forget spider bites, shields and utility belts... That's what really saves their necks. They are no less "invulnerable" than more powerful characters in the context of suspension of disbelief if we are all being honest with ourselves.
Superman's real weakness isn't a green rock... It's his heart. His empathy and compassion, his want to protect and do good for the sake of goodness. Things that pierce those aspects of him are far more lethal to his spirit than any radioactive debris from Krypton or magically empowered weapon. That's the drama for a character like him.