Within my extended family and larger social orbit, I've watched maybe 20 kids grow up. The girls are uniformly successful and seem to have significant support from family, school, and society. The boys have been struggling and have experienced limited support to a degree that I find shocking. Perhaps half will never achieve regular employment, and sadly several seem destined for addiction and early deaths.

This is just anecdote, but for me, I'm inclined to believe 20 data points I can personally observe.

I'm not sure exactly how new this is. Even decades ago, my experience of growing up male is that to a fair degree it's like being thrown off the dock. "Hope you learn to swim before you drown!" The idea that boys are privileged over girls seems like a cruel joke.