I'm in the same boat as you OP, mid 30s so not much time left to decide. I think it is almost certainly a no, but I do feel deeply conflicted by that and I worry that heart/hormones will kick in when it's too late.
We have (almost certainly) decided not to because of the environmental and climate crisis. We both work in that field and the reality is far scarier and more urgent than the majority of the public, politicians and media seem to be aware of. That said I have plenty of colleagues with kids, but they do all talk a lot about their fears. Infact that's the most striking thing about all my parent friends (some who love it, some who dont), they all feel worried and guilty.
I always imagined myself with kids, and we do enjoy spending time with children, so for us this is definitely a "state of the world" decision rather than always knowing we'd be CF. That said, as time has gone on we increasing appreciate the benefits of being CF. We are both quite quiet, have hobbies, appreciate finacial security, and are very invested in charities and volunteering, and we have a very fulfilling relationship with eachother. I also see how much anxiety having children (even when they're grown up) can cause, and I don't think I would cope well with that. I do worry about old age, but it would be selfish to bring someone into the world just to keep me company when I'm old and it's no guarantee.
I think in my ideal life, if I could guarantee a healthy, well adjusted child and have the fincial security for us both to work PT and still have a good quality of life, protected from the worst impacts of climate change - then I would go for it. But I can't guarantee that, having children is a massive gamble at any time, but at this point in history the odds are really stacked against us.