The simple answer is so that the people working in the bread factory can have two days off a week: Tuesday and Saturday. I remember this from my college summers working in a bread factory making "Batter Whipped Sunbeam."
There may be superstitions about the matter but there is no real reason to not bake bread on wednesday, or any other day for that matter.
Some do, some do not
In a bakery.
They probably did.
because they need to for food or for money
YES, they do; all bakers bake cakes. Have you ever seen cake boss. that show rocks.
To bake bread and cakes
Medieval bakers needed to know how to grow, harvest, mill and bake.
Yes but only sometimes....
No they did not they mostly baked breads and that's it
Why do bees make great bakers? Because they put a little honey in everything they bake.
100 If three bakers bake 30 pies in one hour, they are baking 10 pies/baker/hour. So five bakers can bake 50 pie in one hour and 100 pies in two hours.
Mix and prepare the dough, let it rise (proof), then bake the product.
They make goods made from grains, such as breads and pastries.