Or anything else that involves devoting time other beings: homeless feeding drives, mentoring disadvantaged people about programming, working in an elderly home, etc.
The feeling of being part of something broader doesn't only come from having children sorry.
We've had 6 children. It's hectic, loud, chaotic, frenetic, and exhausting. But I'm having the time of my life and super happy to have such a wonderful cacophony trailing around all the time.
Children are special, but not for everyone.
Pull the other one. The judgment is very obvious. Just go ahead and own your opinion. (For the record, I do plan to raise children.)
I put things in stark terms, though, because I think children are, if we're being realistic, one of the only routes to a life with meaning available to the vast majority of people. Most people do not have fulfilling careers. Most marriages fall apart at some point. Children are forever, though.
And I think people need meaning in their lives. If you're a person who is deeply into some other calling and you think that can sustain you for your entire life, then go for it. I can think of many people in my life who could probably find a lot of meaning without children. But they're not the majority of the people I know. And yet the majority of the peers on my Facebook are not on track to ever have children.
Regarding what you just wrote, here's me acknowledging that there is meaning to be found outside of children (which, logically, implies that childless people can find meaning):
> I can think of many people in my life who could probably find a lot of meaning without children.
My argument is about playing the odds. Children are the most meaningful thing in most people's lives. Most people do not find many of the other things they spend time on meaningful (their career and, proxied through their spending, consumption of goods and services). As a result, I think it's a pretty good default strategy to have children. Which is why I promote that strategy whenever somebody is on the fence (OP sounded like they were on the fence, after all).
But if you've thought seriously about it and decide that there's something else you'd rather do with your life, then by all means, follow your heart.
By a long shot.
So I would say this: if you want to live life on easy mode and enjoy all the little pleasures that modern life has to offer, then don't have kids. I say that without judgement; your life is yours to live as you see fit. But if you want meaning, if you want to struggle for something more important than yourself, and if you want to leave something enduring behind when you depart from this world, then have some kids.