Why does it take a year for the cow to produce a calf? Why cant it just spontaneously generate it as soon as the egg and sperm meet? Take the Same question bu

Why does it take a year for the cow to produce a calf? Why cant it just spontaneously generate it as soon as the egg and sperm meet? Take the Same question but replace calf with priest, surgeon, weather forecaster, chartered accountant, musician, chef etc. What is going on in these processes that requires so much time?