It means it took 70 years for the average income and employment rate of socio-economic class of people who used to work those jobs (presumably formulated as some percentile of society by income) to rise back to the the same level.
Employment rates are weird bags of demographics and culture (think women’s rate of workforce participation) as well as economics, so I’m not sure how you extract that particular signal.
70 years to restore income levels across any strata is still not plausible: Even godawful economic growth would compound way too much. Maybe relative share of income for some decile? But now we’re back to asking why we should care about that if absolute real incomes are rising.
> Even godawful economic growth would compound way too much.
You vastly overestimate how much of the growth would be going to the workers in question. Especially as, before fiat currency and electric communication, prices were (relatively) more stable than today, and hence so were incomes, especially for labour work. Why would some factory owner in the 1800s pay his workers more than he needed to find new workers? Most economic growth was captured by capital owners and what would today be known as the middle class, but back then were merchants, doctors, etc. - basically just the tier below the capital owners in the social hierarchy. The vast majority of people were peasants.
