Civilizations probably ended because it's hard to control their own populations. Imagine a society where population is set to 5 billion, the limit only increase

Civilizations probably ended because it's hard to control their own populations. Imagine a society where population is set to 5 billion, the limit only increased when capacity is increased. This is compounded by: 1) a lot of planets are not hospitable for a variety of factors. A society might resent the limit for many years if it was possible to implement such a limit. 2) the technology era is short-lived and not ongoing. A new civilization starts 10,000 years later. How will they even know homo-sapiens existed if a plague wipes out homo-sapiens tomorrow? A few tiny satellites in the vast emptiness of space?