Yup i totally 100% agree with most of what you've said.
I've had several discussions with other writers and the basic conclusion we arrived at is, if you are writing an overpowered character, the interest in the story has to come from somewhere else. In One-Punch Man, it's the interesting characters and humor, etc. Giving the OP character a weakness is always a good one, such as superman's kryptonite, or even a humorous one for comedy measures, like fear of heights or spiders or something.
As for making the power reveal interesting each time and stuff, I think that can be done well by showing another character's viewpoint rather than the omniscient camera view. In other words we see a person get saved by the MC's overpoweredness, but it's the emotional connection with how the character thought they could never be saved etc. So we connect with the surprise and elation of the secondary characters, rather than our own enjoyment of seeing high powered characters.
As with anything there's lots of different ways that a story can go and many applications and counter-arguments for alomost anything you can think of, so I'll leave it at that I think.