That's an unpopular opinion that you've got there... and, a perfectly valid one. I can also get on board with living vicariously through an overpowered protagonist.
But usually--and, a lot of writers and storytellers are taught that this is a must--they have to earn their victories, and really work for it, or else it won't be interesting.
I think that's like saying "happy people aren't interesting"; if zero conflict is uninteresting, then the artist isn't skilled enough. (Although, as a reader or watcher, I can point out aspects that didn't work for me, and zero conflict can be one of them.)
Like, Madoka by the end is essentially god, but she spent so much of the series just being, to us, an ordinary girl, who's bright and does her best, but is essentially helpless. If she became god in the middle of the series, then the ending would feel like it had gone on too long, or we'd keep expecting her to turn evil...which, narratively, she should because why end the story at the middle?
And people criticize Haruhi Suzumiya for being a "Mary Sue" in canon, type of character...but I disagree. For one thing, she never gets what she wants. Every day is conspired to be ordinary to her. Secondly, she has some major personality flaws that Kyon calls her out on (before getting reeled right in what with, "No, it is totally fine to drug and hit a sensitive and meek underclassman"--rubs me wrong, but it wasn't as if everybody will just let her; Kyon called her out, and doesn't seem to find joy in her antics, and I like that because it keeps up the contrast and chemistry and keeps it interesting.)