Right, I'm going to use Star Wars and MHA to go into why its generally a bad idea to subvert an ending.
Spielberg was once interviewed and ask about Kathleen Kennedy working under him. His answer was, she was terrible at her job and would interrupt discussions of the brainstorming a movie's story with her own ideas when she was suppose to be taking notes. The one he really remembers was, "What if he didn't get the girl, but instead got the dog?" Which would clearly subvert the ending of the movie. Now why that stood out, why that is a bad idea, and why he never did a movie with that ending are all the same answer. Because while it would seem clever, it would not lead to a satisfying ending to the movie. Story have a flow to them and the audience has expectation of what will happen at the end. Fulfill them and they will enjoy that story and might read it again to experience that enjoyment again. Subverting the story while one could make an interesting story; it could also leave the audience dissatisfied therefor would not watch it again.
Now, here is Disney Star Wars for examples.
Original Trilogy:
And what if Luke didn't restore the Jedi order, but instead ended up as an loser on a island given up on everything.
And what if Han didn't remain a general and reform the military, but instead went back to becoming a smuggler.
And what if Leia didn't become Supreme Chancellor to restore democracy to the galaxy, but instead remained a general in a galactic government that disbanded their armed forces.
And what if Leia and Han didn't remain together but instead divorce with Han going back to smuggling with Chewbacca.
And what if Lando didn't become a wealthy philanthropist, but instead became a hobo on a desert planet.
Sequel Trilogy.
And what if Rey and Ben didn't get together but instead she got his uncle's farm.
And what if Finn never confessed his feelings for Rey but instead remain her eternal simpering lackey.
Their Tv Shows:
And what if The Mandalorian didn't become the Mandalore, but instead ended on a farm with Baby Yoda.
And what if Baby Yoda didn't become a Jedi but instead just ended up on a farm with The Mandalorian.
And what if Sabine and Erza didn't get together but instead Sabine became a lesbian set up to get together with Ahsoka.
MHA the story start off with the implication that Midoriya is telling the story of how he became the number 1 hero to his successor, who he will pass OFA to. Instead, he lost the quirk, ended up as a teacher for a decade was then given a tech suit, and ended the story with we are all the number one hero. This left fans dissatisfied.
The story of Naruto was he would become Hokage, earn the villagers' respect, become friends with Sasuke while also surpassing him, reform the ninja system, and end up with Sakura. Even if he looked like he succeed with some of that at the end, it still feels like he failed in the spirit. Leaving most readers dissatisfied with the ending. nH and SS fans said they didn't not care about the story and only cared about their pairings happening. Well, once their pairings happened they then complained about how their pairings aren't how they wanted it. The thing is the story wasn't built for their parings and so making them the pairings would always be unsatisfying as either they are unrealistically perfect or realistically imperfect but ultimately shallow because they weren't developed in story but in the fantasies of the supporters.
Its better for a story to stick to a simple one and tell it well then make a complex story full of subversion that falls flat.