Ethical conduct indispensable for attaining enlightenment or Buddhahood
 

Ethical conduct in the form of right speech, right livelihood and right effort are considered to be vital practices leading to enlightenment in Buddhism or Buddhahood.

https://en.wikipedia.org/wiki/Noble_Eightfold_Path

https://studybuddhism.com/en/tibetan...hree-trainings

Ethical conduct is also emphasized in the religious philosophies of Hinduism, Jainism and Sufism for attaining enlightenment.

This itself is a refutation of the nihilist and existentialist premise that life is meaningless and all values and virtues are but abstract mental contrivances without any relevance of their own.

Ethical conduct is important for getting along in the world. But many have become enlightened who were not ethical.