I spent a lot of time wanting things to be perfect, but realized that there's never a perfect time. Other parents and prospective parents I know have said similar things.
Having kids is always a gamble, whether you've got a perfect life or not. You do have to decide if you're ready to shoulder the challenge, and don't force it if you're not, but if you're waiting for external factors to be just right you're probably wasting your time.
"Do not have children" probably isn't going to resonate with anyone. If someone wants that experience for their life it's going to be hard to dissuade, and who are you to make that decision? Should only the rich have children? only the fit? only the wise?
There are other ways to experience the joys of parenthood, especially given that most parents seem to look for any way they can find to offload such joys for some reason. Offer to look after your nieces and nephews for a time, for example. Run a volunteer daycare.
If you are not willing or able to be a good driver, you should not drive. If you are not willing or able to be a good parent, do not have children. Do think about the decision very, very carefully - the stakes are very high. If you don't end up having children - well, at least you didn't end up causing others any harm.
But I understand what you are saying - you should also recognize the situation where you are, in fact, ready. It's like being able to choose when to sit an exam - there is always another week you can spend studying, and at some point you have to decide you are ready once you are in fact reasonably prepared.