Depending on what state/country you live in, care for a disabled citizen may be partly or wholly paid for by the state. The parents may also be able to become qualified caregivers, in which case they can be paid to take care of the child.
It's still a full time job that precludes you from doing a great many normal family activities for the child's entire lifetime. There is also the danger that your state may elect budget hawks who decide to cut funding for the programs halfway through your child's life, leaving you on the hook for ruinous medical expenses. It can also be very unfair to your other children who are going to basically lose out on activities because their disabled sibling requires too much care.
I agree completely about all of the challenges, hardships, lost opportunities, and unfairness. It is an awful situation to be in for everyone involved and no amount of money in the world could ever make up for that.
