The figures for the number of people (in the US at least) are that around 30 to 50% of people get a will done before their timely demise.
I currently do not need to make a will and feel no inclination to do so because 1) I do not object to the current line of inheritance and 2) I am not feeling warm enough to make bequests to anyone\anything anyway - if I die, I die, and will remain cold. But apparently not writing a will could delay the moneygrubbing process due to vagaries that arise from not being certain if there is a will.
On the opposite side of all this, one of my uncles is...what my mother used to call (I believe) "a philanthropist" with a strong level of disgust...an apparently a clever and disturbing way of stating that he is a frightful queer. As someone who is probably unlikely to have descendants, I should of course be kinder towards him!