As for the premise itself, I find it doubtful. All of my friends below age 30 (i.e. past millennials) have a much stronger working knowledge of marketable skills than I did at a younger age, as well as more open and free resources to develop them. It is most often access and connections that block their career progress, not capability.
Boomers rode a wave of affordable education and economic growth. They did not see fit to secure those benefits for their own children in the way their parents did for them. Their final legacy is climate denial and environmental damage that will haunt their descendants for generations.
Boomers were the generation who decided to cook food on plastic instead of normal pans because it saved them a few seconds of cleanup. Millennials are the generation who grew up eating food cooked on plastic and now have unprecedented rates of early onset cancers. This type of pattern touches many aspects of the intergenerational relationship in the US.
I am curious about this. Do you have a source?