They don't. A single BASIC robot could replace 90% of what you see in the video. Is there really a need to pay someone for blowing a puff of air on a matchbox car?
I'm sorry but 90% of these jobs are useless. I can't imagine anyone can feel ANY job satisfaction inspecting the "aesthetic" of a matchbox car :( Or literally blowing a puff of air on 50,000 of them :(
Well maybe it's not about the job satisfaction to them or what is important . Maybe just putting food on the table for their kids and family is what matters.