Wheat farming around the time of the McCormick reaper.[1] Farm employment dropped by half between 1900 and 1930. Production up. Wheat cheaper.

Coal mining from 1950-1970. Production up. Coal cheaper. Employment way down. Classic book, "Night Comes to the Cumberlands" (1963) on how Appalachia became really poor.

[1] https://www.gilderlehrman.org/history-resources/teacher-reso...

I'm sorry I don't have better statistics but after the dot-com bubble burst in 2001, I think it took roughly 15 years for the stock market to bounce back. Though I could be wrong, I think unemployment was also high, including in the tech sector.