Do you consider yourself to be necessary? Like, for mankind? Probably not: you're just one of eight billion nearly-identical people, and if you vanish off the surface of the planet, the economic loss will be basically zero. Heck, if you're of retirement age, you're probably a net burden for the society.

But that doesn't sound like a good argument to ride off into the sunset, right? You probably enjoy living and it does make a difference in the lives of some close friends and relatives?

We don't organize societies around ruthless efficiency optimization, we organize them to be at least somewhat hospitable to humans and human enterprise.