Dear Puckish Fiend,
You seem fairly interested in economics, so you might want to look into learning about a couple basic economic concepts.
#1:
Next time you go shopping, pay attention to how many decisions you're making each time you put an item in your cart. How do you pick which item is "better"? What trade-offs are you making? Is the healthiest cereal also the best tasting cereal and the cheapest cereal? What factors go into deciding what brand of bread to buy — quality? organic? shelf life? price? size? number of slices? taste? calories per serving? other health facts?
The reason there is a variety of products is that different products meet different needs. The variety of similar products with different strengths provides benefits to society — because one size rarely fits all. And, in fact, the fact that we must pick and choose which attributes we prioritize is what makes competition possible in the first place.
(This ties heavily into the theoretical concept of "substitution goods," if you want to look it up.)
#2:
You might want to do some reading on the concept of "public goods."
Here's a brief, fairly simple article, and the ever-great Planet Money has a
recent podcast that goes into the issues of public or private lighthouses and autopsies. Interesting stuff.
