This seemed like a (mostly) thoughtful take.
Aside from stating the obvious (lawsuits and recent membership changes have adversely impacted participation), he honed in on 2 other factors:
1. Civic engagement (Elks Club, Optimists, etc.) and church attendance has decreased in the US. These organizations have been major sponsors of the BSA and their parallel decline has resulted in less support for Scouting.
2. Society's definition of masculinity has widened. Fewer young men are expected to hunt, farm, fix cars, or join the military. Scouting was once viewed as an age-appropriate way to introduce self-reliance to boys. Today, those hard skills are less important in the information economy.
I especially appreciate the second point. I doubt I'd meet the standard of 1970s masculinity. I'm not handy. I maintain my home to the minimum standard and hire help the second I get in over my head. However, I do make a decent living. Plus, we live in a safe neighborhood and are on track for retirement. My son also has everything he needs, including most of my attention outside of work. By the 2020s standards of masculinity, I'm probably doing just fine.