From Practical Economics
Before we can understand economics with any degree of expertise, there needs to be agreement that:
We live on an Earth that is finite and limited.
Humans are not perfectible and have insatiable desires as a part of their nature.
Putting these two factors together, basic reasoning tells us that:
Since we live with scarcity we can‘t meet every desire.
We will have to make choices; taking into consideration trade-offs or costs in making decisions.
The choices that are made will either increase or decrease our efficiency to the betterment or detriment of the entire society. The quest is to increase the number of desires reached while decreasing the resources used to reach them as effectively as possible.
When scarcity is ignored in the decision making process, ideals that can only come true in a world of unlimited abundance are embraced without the worry of the devastating affects of such utopian dreams. In other words, acting upon what might sound like a glorious and noble idea can, and often does, have the opposite affect on the health and standard of living for everyone.
Because of scarcity, we can only hope for a best case scenario between a myriad of choices, each having an associated cost. Wasting time with theoretical "what ifs" may make those with the time to fantasize about perfection smug, but it does little to raise the standard of living and quality of life for everyone