His best friend is also a billionaire, and his home is a giant ice castle filled with alien luxuries, robot butlers, and super weapons. He spends the other part of his free time on a literal space station. It's comics so if you want to cherry pick nonsense we'll be here all day.
I actually read Superman comics fairly regularly, and I can't begin to tell you the last time one was actually about his human side. The last one I can think of was American Alien which was 5 years ago and in an alternate timeline. Now, I don't read every issue ever released or anything, but those stories are rare. And yes. Tony acts like an actual human. Superman does not. It's all him flying around, punching things, and lamenting how powerful he is. Everyone always says the best Superman stories focus on his humanity, but in reality those stories are extremely rare. He has small town roots, but his actual story is about leaving those and moving on to bigger things.