I'm hunting for a new job for the second time in less than a year, and I'm honestly a skilled professional with over 10 years of experience, with a lot of proof that I do great work. The labor market is stupid right now, just down right stupid. Full of executives searching for short term profits rather than anyone wanting to actually run a company well. That's alone is a huge reason, on top of everything else. I don't even know if I'll have stable employment, and that means I don't know if I'll have stable health insurance - so genuinely what are any actual incentives to my generation to have kids? Literally are there any beyond just "you have a kid now"

The parts of the world with the most population growth are generally also the poorest. Richer countries have fewer children, and within those countries richer people have fewer children.

I'm not saying that your concerns about your quality of life are invalid or that they aren't the reason you personally don't want children, but they don't explain this general phenomenon.