Every time people have bitched and moaned about people losing their jobs, the result was more people employed earning more for their labor
Um...not really clear on that, but I know that realistically speaking, my job as an engineer is to eliminate jobs through task automation and streamlining paperwork.
do you seriously think anyone in the middle or lower class would be better off living 50 or 100 years ago?
50 years ago puts us back in the mid-60's, when there was still plenty of good paying factory work to be had, and middle or lower class had more upward mobility, housing was still (relatively) cheap, education was cheap, pensions were still a thing, along with miniskirts and free love. I fail to see the downside here..