Well, for the most part, we are machine tenders. In order for the quality of your eggbeater, or your alternator, or your squirt-booster engine to be predictable, and reliable, and dependable, it has to be manufactured to pretty exacting tolerances, and humans are not capable of the kind of precision required to produce these things in large quantities.
A single human- skilled human, that is, can make a single part so perfect as to defy the imagination. But the system falls down when you get to a thousand of those parts, or a hundred thousand, or a billion. At that level, when you are supplying parts ot the known universe, they have to be perfect, and every one has to be perfect. And there can be no failure.
Ande no human can do it. It is at the core of human nature to despise the repetetive (though left to our own devices we won't change a thing about our lives). We hate doing the same thing over and over again, because it drives us batshit crazy.
Additionally, a lot of the piece parts my customers make are damned difficult to manufacture, and or even pick up without heavy lifting equipment. Let alone dangerous, or sharp, or toxic, or gamma-hot.
So droids do the work. Built to do the repetitive. Built to do the drudge work. Incapable of reason, they are capable of repeating a task for as long as their servos and bearings and lubricants hold together- and Big Yellow makes droids that have a mean time between failure that I wish I could get for my knees.
Subsequently? Humans tend to clean up machine poo. Each type of machine manufactures a specific type of component with a specific set of materials, and the by products pile up quickly and need to be removed lest the machines get covered in it, and encased in it.
The machines are well trained, and tend to leave their offal in neat piles inside containers, which humans with forlifts take off to be re-fired or refined. It's not hard work, it's usually not too dirty, and it's essential. And the people cleaning machine poo tend to be better paid than their skilled trade counterparts a generation earlier.
I decided I would never spend my life cleaning the litterbox for an oversized cat, so I design and implement systems. The work isn't hard, though some tasks can be, and the overall impression is one of creative goofing off.