I also dislike when the underdog genuinly starts off as an underdog and is just given a cheat code which is played off as "hard work and determination".
Like the main character of My Hero Academia. A person born without super powers in a world full of super heroes. You get excited at how he will overcome his limitations..... and the answer to that is be given the strongest power in that world and get even more super powers on top of that.
It is especially annoying how the surrounding characters act like it isn't a cheat code.
Funny thing is in that universe there is a character called Lemillion who had powers with drawbacks and had to learn to take advantage of them. A true underdog making the most of the cards he was dealth with. He should have been the MC of the show.
Mind you I am not saying Lemillion should have been given one for all. Just see that he should have been the main character. One for all could be a mcguffin for the heroes to keep out of the hands of the villains instead of using it like a cheat code.