Alchemy is unscientific by its nature - let's mix random substances to get gold.
Materials science follows in the footsteps of the alchemists, keeping alive the grand tradition of mixing random stuff together to see what happens. They too are frequently mixing things together in the hope of getting specific outcomes - usually it doesn't work.
Science is about how people deal with evidence. There wasn't any reason to think that gold couldn't be produced by mixing stuff together in the days when alchemy was popular. After all, a bunch of other substances could be made by mixing things, and it is obviously possible to mix liquids and get solids.
We didn't learn alchemy. We learned about alchemy.
Sometimes surprising and interesting things happen when you experiment. Maybe goat piss with hair of a virgin seems weird, but burying shit in your backyard for awhile, digging it up, and mixing it with burnt wood seems pretty odd too when you think about it.
If memory serves, one of the big reasons for Britain’s naval supremacy for a long time was their discovery and exploitation of large deposits high-quality of saltpeter in India. Before that, they had “saltpeter plantations” with rows of organic waste soaked with human an animal urine and left to dry in the sun. Before that, it was groups of the King’s men going around the countryside and scraping the stone foundations of buildings and cemetery monuments.