There’s a story on royalroad called Emergence, about a victorian-ish era dude who ends up shipwrecked alone on an island filled with dragons: I love that the story treats penicillin as one of the most powerful things he has access to, along with stuff like the radio.
Like yeah sure guns are scary, but so are massive claws. The ability to cure what has hitherto been utterly untreatable guaranteed wasting death, however? Basically the power of a god.

Another story, Delve, is about a guy being isekai’d into stock fantasy world with DnD-esque mechanics and going “well that’s fucking terrifying, i’m starting a union and inventing OSHA”.