Honestly, Wattpad's algorithm is so hit-or-miss for finding quality stuff. I'd skip searching "top" lists directly there—they're often just what's most recently updated or has the most generic tags. I've had way better luck going to the My Hero Academia tag, sorting by 'Completed' and then 'Hot'. You filter out a lot of the abandoned WIPs that way. A story that's stuck with me is 'Swimming Lessons' by umisabaku. It's a Todoroki fic, but the character voice for the reader insert is so distinct and witty, it never feels like a blank slate. The author nails the balance between the school setting and the slow-burn dynamic.
For a newer reader, I'd actually recommend checking out the 'Bakugou x Reader' tag and looking for stories with detailed author's notes. Sometimes the writers who clearly outline their chapter plans are the ones who actually finish them. 'Explosive Temper, Gentle Heart' was a solid one that completed last year, with a really thoughtful take on Bakugou's growth. Just be ready to sift through a lot of 'Y/N gets a quirk' plots to find the gems that focus on character interaction over power fantasy.