Zoning laws

I am trying to understand the reasoning for some of the zoning laws.
I thought that I owned my home. I have to pay taxes just to own this home. Then, the government is going to tell me what I can and cannot do. I have a decrepit fence that I inherited when I bought this home. It is falling over, has holes in it and looks a mess. I must pay money to get a permit to replace my fence, but my neighbors can spray their lawns and trees with pesticides that are poisonous to wildlife, our children and our environment and linger in the environment for decades, and do not need a permit to do so.

So replacing my ratty fence with a nicer fence that hurts no one, is not allowed without permission and paying a fee, but they can poison the world, just so their lawns don't have dandelions and need no permission to do so. I remember reading an article about a woman who was told to cut her wildflowers down that she planted, because they were "weeds". The definition of a weed is a plant that is not valued where it is growing. So who needs to value this ? The homeowner that planted the wildflowers to attract birds or the government, who leads us to believe this is a free country, yet we never really own our homes.