Combine that with wealth stratification, Hussle culture, and the complete lack of any real social safety net and if anything I'm surprised we're doing as well as we are.
I don't think it's a single issue by far, but if I had to peg one aspect as the worst offender, it's isolationism. There's strong correlation between drug use, depression, suicide, and lower life expectancy in places with power population density (Alaska, Noth Dakota, pretty much any small rustbelt or mountain or southern town)
When there's nothing to fill the emptiness, people turn to drugs and overeating just to feel something.
https://www.pnas.org/doi/10.1073/pnas.2022472118
https://en.m.wikipedia.org/wiki/Suicide_in_the_United_States...