Simplicity and selflessness are not the basis of Taoism. They are merely the by-products you get from your experiences when you practise Tao.
Taoism started with the book Tao Te Ching written by Lao Tsu, a Chinese philosopher who lived around 550 BC. The first sentence in Tao Te Ching is: “The Tao that can be told is not the eternal Tao”. The following is a part from the Introduction of the 2012 edition of Gia-fu’s translation of Tao Te Ching written by Jacob Needleman:
“These words are among the most famous in all world literature. They were first offered, however, some 2,500 years ago, not to modern Western people like ourselves, but to a people and in a place, ancient China, far removed from us. Any work of art that communicates so enduringly over such enormous reaches of time and cultural diversity addresses, we may be sure, the essence of human nature and the human condition, rather than sociocultural aspects peculiar to this or that society…
The Tao Te Ching is thus a work of metaphysical psychology, taking us far beyond the social or biological factors that have been the main concern of modern psychology. It helps us see how the fundamental forces of the cosmos itself are mirrored in our individual, inner structure. And it invites us to live in a direct relationship with all these forces. To see truly and to live fully: This is what it means to be authentically human…”
So, Taoism is not about simplicity and selflessness, but about seeing what it is. But to see is extremely challenging as it is very abstractive to be able to see. As to see is not to presume, do, create or unconsciously judge. One needs to forget oneself and open to ultimate reality, to get it, to emerge oneself to the nothingness and the wholeness before it becomes everything else, before the big bang.