system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why must there always be economic growth?

When reading news articles or watching TV, we hear that economic shrinking is bad, stagnation is disconcerting, and growth is good. 

Is a constantly growing economy even feasible? What's wrong with stagnation or shrinking?
gpt
1) Population is always growing, barring some horrible catastrophe or war. Therefore, economic output must also increase in order to create the jobs, and goods, all those new people need. This is true just about everywhere.

2) The value of money is almost always inflating, so people need corresponding wage increases in order to continue to afford to live. As wages stagnate and prices continue to grow, eventually people can't afford to pay for everything they need, such as rent/mortgages, food, gas, cloths, etc. Constant economic growth makes businesses more money, which results in them paying their employees more. (In before some socialist comes and rants at me about growing wage gaps or whatever. This is an economic principle, and yelling at me won't change that)

3) If the economy isn't growing, then it's shrinking. This translates to businesses shutting down, people losing their jobs, and less tax revenue for the government. Each of these things results in, in order; fewer goods for sale, resulting in higher prices; fewer people with money to spend, resulting in even more businesses closing; and the reduction of government programs, which means more people without jobs. Combine these problems with either of the previous examples and you have a recipe for massive unemployment, exorbitant prices, and a bankrupt government that continues to spiral downwards until the country collapses. 

TL;DR, An economy that isn't growing is like a body that can't make new cells. You'll be dead in a week.