I think very few understand the cruelty in Horikoshi's decision to have Midoriya lose the OFA and how mediocre he was in expressing Izuku's loss, while functioning as a source of emotional support for other characters in the final chapters. Since Midoriya obtains OFA, he shows great fear and rejection of his past self, his quirkless version, the one who was isolated from everyone around him with his mother as the only person who treated him with some basic human decency, a boy who self-destructed because he was terrified of being the deku who can't do anything. Izuku's rejection of his previous version is so great and it's taken in every part of the manga and his self-destructive tendencies.
The ending doesn't fix any of that, Horikoshi's mediocre writing ends with Midoriya resigned, returning to what he was and who never managed to express himself for it, away from his friends and his main dream, so that later his "problem" is fixed without him had the possibility to intervene, because even the surprise is that everyone made a suit ignoring the person who had possessed OFA for two years and learned to use various quirks and how he felt doing it. The problem is not that Midoirya chose teaching as a career, the problem is that Horikoshi's mediocre writing made it a losing option, it never solved Izuku's self-esteem problems and I'm supposed to believe that this is a good ending?
I think it's got less to do with "mediocre writing" and more to do with mediocre readers not understanding that mangaka don't get to retire - they take breaks then return to work. You've ignored or missed every single continuation hook left behind in the final chapter and prior, now complain about Horikoshi as if your inability to read details without spoon feeding is his problem. Have you ever had a single original idea or theory that wasn't lifted from someone else?
Answer me a very simple question. Why do you think Shigaraki appeared in the last chapter?
