Humans in the west work between 1/2 and 2/3rds the number of hours worked in 1870. The ‘winning’ of the 8 hour work day wasn’t until 1938 in the USA, but there’s no correlate drop off. Instead, it’s the congealment of numerous technological and social changes over time.
So far no labour saving device in the history of humanity has resulted in a long-term reduction in employment.