The world is not medieval. Casters can make water pure by touching it and produce food for a dozen people every day, at low level. They can cure any disease in seconds. That changes the game early on.
Later, we can move goods instantly, create them from nothing and change htem from one material to another. That changes the economy.

Really, in a world where casters can stop time, go for a cup of tea in heaven in the afternoon, talk to gods, summon rainbow coloured flying snakes, clone themselves, build golems out of stained glass and demon parts and create new worlds that are made out of rubber and prone to earthquakes, what is so bad about someone creating a chicken with alchemy?