As many have pointed out, parents are not doing their kids any favors by letting this dynamic develop. They're not doing themselves any favors, either. For example, DH was always, always in line behind his brother. BIL's selfishness and grabbiness was either 'cute' or 'well, he's the oldest'.
BIL is now 34 and back living with his parents. He does have a good job in his field, but his field doesn't pay that much. He took a year off to go to trade school with DH, but again, opportunities for working in that trade are not overly common, and opening your own shop takes a lot of capital. DH was lucky to get a job; doesn't pay that much, but enough, and the company is located in a beautiful area where we've dreamed of living.
BIL and FIL have had numerous squabbles and apparently nearly came to blows last week, so BIL is now flouncing and talking about moving out of state, changing careers, blah blah. Guess who's *not* volunteering to see about a job for him, or offering him a place to stay while he gets sorted out? He's burned his bridges with his closest family and anyone else who spends more than 15 minutes with him, so he's got no support for this big move he wants to make.