I don't think it is the monthly mortgage. I think it is routine maintenance and repairs, replacing worn out furnishings and other items needed for a good quality of life, making property tax payments, and meeting a host of unplanned costs that home owners experience. A mortgage payment might be fixed, but other expenses will rise with inflation. Even if modest, a dollar today will be worth only 50 cents in twenty years. If they aren't, you must.
Money is one variable.
Family is another. In my opinion, the probability of success is higher if your child needs little supervision or assistance. Professional staff come and go. Unless you are very lucky, you should not expect, over an extended period of time, that the same people will assist your child. I think the success of home ownership increases if you have family or friends to count on as a reliable back-up when professionals are unavailable or unhelpful.