I rather suspect that behind every Olympic medalist is a resentful sibling.
I have spent a lot of time observing the impact of significant sporting talent on dh's family.
Mil and FIL - both decent people and loving parents played a sport to a pretty high level before they had kids. They had 3 kids. BigBIL, dh and LittleBIL.
When BigBIL was 9 or 10 his parents got him to try the sport. He didn't enjoy it and went and joined Scouts instead.
When dh was 9 or 10 he also tried the sport. Loved it. Started playing. Within 6 months he was "spotted" and started getting high level coaching. BigBIL was 14 by then so could stay at home but LittleBIL was only 2 or 3 so was dragged along with his toys. Many a family photo at this time of dh with bigger and bigger trophies and LittleBIL with bigger and bigger toys.
When BIL was about 5 he announced he wanted to play too. He was too little really but FIL started teaching him and from then on he would be found playing the sport's equivalent of keepi-uppy in the background.
At the same time dh started playing internationally for his age group. It occurred to one of the coaches that the much younger brother of his new star may be a good way to get a new even sparklier star.
LittleBIL started being coached properly.
When dh went to university at 18 he was the top 18 or under in his country but not good enough to make the senior team and LittleBIL was 11 and the top under 16 in the country.
When I met dh two years later LittleBIL was 13 and in the senior team. (And significantly better than dh.)
Don't want to reveal exactly what happened next (too identifying) but BIL is a commonwealth medalist.
Dh is very very proud of LittleBIL. BigBIL is proud but also slightly resentful about the family obsession with the sport. (Dh has no clue about this but to me it's pretty obvious.)
What saved the family was the big age gaps. BigBIL was nearly 18 before LittleBIL ever played.
Had the three lads had small age gaps I think the family could have been very damaged.