It just doesn't take that many people to do all the stuff.[1] The automation revolution happened a long time ago.[2] Peak manufacturing employment was in 1979. Agriculture is down to 1.4%. Making stuff (mining, construction, manufacturing, and agriculture) is at 14% and dropping. Those were the classic blue-collar jobs. They're the ones where large numbers of people were employed doing repetitive work under close supervision. Many of those jobs were unionized and paid OK. Even for people with IQ below 100. Not any more.
For a while, "services" employed more people. Then came cheap computing and the Internet. No more file clerks. Much less paper-pushing. Fewer retail salespeople. Fewer bank tellers. Both retail and finance are dropping in headcount.
For a while, "services" employed more people. Then came cheap computing and the Internet. No more file clerks. Much less paper-pushing. Fewer retail salespeople. Fewer bank tellers. Both retail and finance are dropping in headcount.
That's what happened.
[1] https://www.bls.gov/emp/tables/employment-by-major-industry-... [2] https://fred.stlouisfed.org/series/MANEMP