I understand disabilities and disorders can hold adult children back, if that isn't the case I'm curious where things went off the rails, as a soon to be first time dad myself. This stuff worries me, that regardless of all the investment and good parenting in the world, that my kid(s) can fail to thrive.
And if there's one piece of parenting advice I can offer, it's this... your kids are their own people. Parents only have just so much control. (The flip side is also true; at a certain point, you can't just blame your parents for your own life.)
My kids are still pretty young (<10) but this is something that I increasingly understand/believe the older they get. One of the most surprising things for me as a dad was seeing how different my kids are from each other, even when being raised in exactly the same environment. This has really reinforced to me the idea that people are really their own people, and there is only so much a parent can do to influence what they'll become later. (And yes, this has also given me reason to reflect on the idea that I can't hold my parents responsible for my life choices - definitely cuts both ways!)
As a parent, you can provide an example of behaviour and whilst the child is young provide restrictions and discipline as necessary, but beyond a point, your work is done and it's up to them.
He has to go for lots of reasons. One is that I'll have 11 other kids to devote my resources to. Another is that a bit more of a push might get him to fly. Another is that I've seen my two youngest brothers still living with my parents, and it horrifies me. While one of my brothers has an excuse (needs watching for schizophrenia medication), the younger of the two has no excuse: over 30, has an MS in computer science, badly addicted to video games.
The video games really do provide an escape from activities that would require learning social skills. If your social skills are bad, you might want that escape, but that isn't making the situation any better.
I have a BS degree in computer science from UMass Lowell. I started the family, married, moved into a place of my own, and started an OS kernel developer job just a bit before finishing the degree. At that time, back in 1999, my starting pay of $48,000 ($73,628 in 2019 dollars) was more than my wife's parents made together. You can wait forever trying to get your life into a perfect state for starting a family, or you can just get on with it. Once we had two kids, my wife gave up on that same degree with 75% done.
I currently work for a government contractor, doing low-level software: https://news.ycombinator.com/item?id=20088647
I mostly stick to living in small affordable cities like Melbourne, FL. The area I'm in now is just large enough to have commercial jet flights, 4 each way with Delta and 3 each way with American. Houses have a median price of about $150,000 here. I paid about double that to have a big house (3500 sq ft, 0.39 acre) less than a mile from the beach. I paid it off in 8 years.
Unless you count opportunity cost, there are no child care expenses. My wife does that. The kids are homeschooled, with dual-enrollment providing free AA degrees that have fully transferable credit to state universities. There is a scholarship that should cover the rest, except that we botched the application for the first two kids.
Food is the big expense. We seem to spend over $40,000 per year on it. About half the time we hit the out-of-pocket maximum for health insurance, which is something around $11,000 if I remember right. (skull fracture, major rib cage surgery, more rib cage surgery) After that I don't know, but it might be electricity or home insurance.
My state has no income tax. I don't really pay the federal one, due to the kids.
Maybe the important point is that I just went for it. Sensible career and expense choices help, but the main thing seems to be this: You can wait forever trying to get your life into a perfect state for starting a family, or you can just get on with it.
Lots of little reasons add up. There was never a definite decision. I guess I got fond of having so many kids, and I got used to the chaos. I saw my wife's uncle fall apart after his only daughter died, so redundancy seems wise. My wife is hard-core Catholic. Making kids is fun. Maybe some will visit when I am old.