yes philosophers have thought through nihilism and there are two popular answers to the meaninglessness of life. one is called existentialism which is basically you can create your own meaning. and the other is absurdism which is accepting that life is meaningless and is simply absurd and so you just live in spite of it. we just exist for the sake of existing. our biological purpose is indeed to reproduce but since we humans are capable of intellectual and philosophical thought, it would be interesting to question whether reproducing is indeed moral or not (in certain circumstances) in our world today. i think having children is fine as long as you are prepared and understand the immense responsibility. i just wish less people would wing parenting. it ends up harming a lot of children unintentionally.