I do both.

I certainly answer my share of questions on this forum. I also give blood, spend hours almost every week on community volunteer activities, donate a little more than 10% of my income to various charities, donate books to libraries, and so on.

But I also learn a lot from this forum. I benefit from all manner of community programs. I take advantage of free open-source software that others wrote. And so on.

We're all symbiots for each other. No way around that. Best way to live is to live for yourself AND for others. Live for your family and your community and your own benefit, all at the same time. Take a wide view and make all your actions count as much as you can. If you're a member of the human race, it's pretty easy to see that benefiting the race as a whole can benefit you, and that benefiting you can benefit the race. Even small actions count.