I really enjoy these science anime that show our heroes creating and progressing on inventions slowly as part of the story.

Another one that doesn’t really focus on science, but does involve science is Ascendance of a Bookworm. Where our protagonist Myne gets isekai’d to a medieval fantasy world and makes it her life goal to bring books to the masses cause she loves to read. We see her invent paper, ink as well as other modern conveniences like shampoo, that kind of stuff. It’s more low key than most science anime, but our hero is not a genius like most others are.