You simply do not understand what cosmetics is about. As Many others in sub-replies to this one. One could say you do not understand human nature, DNA or anthropology.
Cosmetics is not about something "unnecessary" it is about increasing your chances with reproduction.
And now tell me what more important thing that reproduction could be encoded in our genes?
Second to reproduction is feeling well. For whatever strange reasons our history shaped society, people today have to live in it and they, of course tend to try to maximizes their happiness.
Some People feel better when they get attention (again DNA and anthropology). Of course YOU want to go to space. And by you I mean all in this thread who despise cosmetics in favour of space travel, simply. Because humans are not simple we have deep contradictions embedded in our DNA and society forged traditions.
Yes I agree with you all very much we should go to space BUT to be able to do so we first need to find consensus on each individual happiness weighted against the demands for happiness from other people, of the whole world. Its as simple as that. And I don't have to tell you that concepts like nations do not necessarily help in achieving that.
We are moving up the ladder(https://en.wikipedia.org/wiki/Kardashev_scale), towards a global society. In that we can not ignore a single persons mischief as we do today.
I hope you see see that its not about "superficial" cosmetics, but about us as humans. And how to be happy, all around the world. We can and should do it but it will look very different to what the world looks today. And of course our anthropology is fighting us here hard again. We want the result of change but not change what is necessary to do that, that is to change ourselves (To acknowledge other people, be more peaceful and thoughtful about resources, etc..)
So again what do you think about cosmetics?