I don't want kids personally, so I don't know how the thought of never having them hurts you, nor how much this will help, but this is my experience:

I will never have kids of my own. Because of this, I have the time, energy and want to be a positive adult influence in a lot more childrens lives than if I had to raise just a couple of them full time.

And I don't mean just giving cool gifts intermittently, I mean discussing life and death, practicing managing emotions and using empathy, and building confidence and self-reliance through play and conversations. Talking about source checking, the effects of advertising, including hidden advertising in social media/influencers, and practicing body positivity. Working out how to handle peer-pressure, how to change your mind even if you've gone along with something, to say no when you're uncomfortable, and how to apologise when you've been unkind or even accidentally hurt someone.

There are so many things that kids need to practice over and over, and so many things they may not (want to) listen to their parents about, but other adults are still cool (especially at certain ages). That's where we come in. The other adults. The positive adult influences. The ones who are really good with kids, and with the ability to be really good to more than just descendants.