Even if you have kids at 70, there are good odds you'll be alive when they are 18. Provide for the kid, teach them right from wrong. Let them know they are loved and you have done better than every dead beat dad and sperm donor to single mothers out there. There is nothing egotistical about having kids, at any age and doing the best you can. Even if it's a decision based on ego, do the prior mentioned things and it's still a net positive for the world.

I had kids because I wanted to pass on my line as nature made me. Does that make me egotistical, maybe... Who cares? I love my kids, see them as both an extension of me, their own people and a positive I brought into the world.

No, it’s really not. The rate of increased birth defects for older fathers is quite small[1]. It’s advanced maternal age where you see the multiple orders of magnitude greater chance of serious problems.

[1] https://pubmed.ncbi.nlm.nih.gov/17164268/

I know, I have kids and it's awesome