I'm a 4x egg donor.
I started when I was 25/26, and ended when I was 28. Like you, the money was the initial draw, although I thought the idea was "cool."
This means that I have multiple children, which I actually don't really think of as "my" children. I don't think of myself as having kids with multiple strange men. They're my genetic offspring but they're not my children, they're not my kids, and I have no connection to them.
I read a LOT about how the children felt. I read a lot of heartbreaking stories, actually, from the children's perspectives, but there's also bias in the responses. You're more likely to write about something that was especially sad or hard on you. There are tons of children out there who are the children of donors and are happy and healthy and well adjusted. Not all recipients of sperm/eggs are going to be good parents, and that's just something I have to live with. My comfort was knowing that most of them would be going to well-off homes, which meant they'd hopefully have not difficult lives.
TBH I didn't think at all about what if my kids showed up and were more successful or whatever. Why would that even matter
. All I would want to know, if they showed up in 18 years (and I hope they do), is that they are happy. That would matter the most to me. That's the only thing I can really think about when I think about them-- that I hope they'll come look for me and I hope that they'll be healthy and happy and only curious, not feeling like they are missing something. I'd love to introduce them to my family, their biological family, but in the end I want them to understand that family isn't blood, but who loved you and who cared for you and who was a part of your life.
I registered on 23andme, solely because I wanted the donor kids to have a way to find me and connect with me if they chose to.