Why is rapid economic growth of a country/region unsustainable?

Question

need cases studies mainly + and main reasons why economic growth is unsustainable or indeed sustainable

Answer 1

because every one will get richer and hav mor money 2 spend , thus pushing inflation up, which then pushes the price of everything up making everything too expensive for most people. for example zimbabwe with an inflation rate of a few hundred thousand- the only country in the world where billionares are considered poor