This is very interesting but I don't see any downside in my family's favored.
Your experience was quite different from mine. I was still beaten and lashed out at, just not nearly as much. The biggest difference for me was that I also got praise. My siblings did not.
For me, I used my status as 'golden child' to try to get my parents to calm down and to protect my siblings as much as I could. It was not uncommon for me to take a beating that would have gone to my siblings, because I knew it wouldn't be as bad for me as it would have been for them.
As a result, I turned into an adult who felt that I had to protect all the "underdogs" in the world. The pressure was enormous and drove me to drink. I had to be perfect. I had to keep my place as the golden child or the fallout on my siblings would be horrific. From the time I was 14, I tried to hold my family together. Now things have happened that are far too big for me to do that. The family is falling apart, but at least I've had enough therapy behind me to not hold myself accountable for that fallout.
I lost my place as golden child as an adult, when my dad transferred the crown to a family friend. He is now getting to feel the weight of that crown as he tries to figure out how to minimize the legal fallout from the trouble my dad's gotten himself into. He's discovering that that crown weighs a LOT and he's experiencing a bit of what I did, except that he's pushing 50 now (my dad is in his 70s) so he didn't grow up in this environment, so while it's hard for him, it isn't nearly as bad as it was for me.