"Garbage collection, sewer maintenance, pest control, slaughter house, janitor, ditch digger etc."

Some of these jobs can be done on an individual level, like bringing your own trash to the dump or the recycling center. Keeping our own spaces clean. If we had to take individual responsibility for these tasks, maybe we would think twice about how much waste we are producing, or how we pick up after ourselves at home and at work.

If no one wanted to work in a slaughter house, maybe we would eat less meat? Maybe slaughter houses would become obsolete and we would return to small farming?

A lot of these jobs suck because they are hiding abusive practices such as factory farming, over-consumption and waste.

Another perspective: if the positions were not filled we would have an accumulation of undesirable consequences which could lead to innovating the way we do things, which is currently doing them the cheapest way possible. Always worshiping the bottom line.

Things that could be innovated: composting toilets, biodegradable packaging, clean energy, industrial waste reduction etc...

That is my input!