In truth, we don’t have a way to measure the ‘goodness’ of our morals, especially without being biased by those same morals that have been fostered in us since birth. This excuse has often been made to defend passive ideologies like cultural relativism, and actions such as female circumcision in parts of Africa.
Existentialism is often confused with Nihilism for obvious reasons, both philosophies famously discredit all of our assumed virtues, by confronting them with hard logic and realism.
However slight, the difference be Existentialism and Nihilism is distinct. When faced with the void, Nihilism offers nothing to replace the meaning it subtracts from life, where Existentialism simply allows you to lower your standards of happiness to level that simply existing satisfies, ensuring a content life.
In our human quest to prove ourselves, to add meaning through competition and comparison, we are slowly poisoning the only source of known life in the Universe in the Earth. Because of our arrogance we have broken the natural order of how creatures should act in accordance to their ‘special purpose’.
A common philosophical theme, ‘special purpose’ is loosely, our reason for being in existence, and I would contend our purpose is to appreciate the ability to appreciate or existence.
The end goal was never something to accomplish in our lives, the end goal was to make it to a state of existence where you understand you exist.