I never get this argument. "...with no clear reward or incentive.", isn't having electricity enough of a reward and incentive. The same goes for everything else. Why wouldn't having the product or thing you rely on in daily life be incentive enough to produce it? Like why do you need a specific reward for working a power plant? What's that reward now? Money? There are enough other jobs they could work to make money. They chose to work in a power plant because believe it or not, some people just find that shit interesting.

For other things like garbage collection that doesn't require too much job specific expertise I believe a rotation system would be the best solution though if you don't find enough people doing it voluntarily, but maybe you would. People do free labor for community events all the time, sell or make food and beverages, plan the event, help build stuff for it. For many people the community recognition would be incentive enough.

I just believe we have enough people with diverse interests and goals to make this work. Some people thrive on community interaction, some people like to do technical labor or science, etc.

Imo in the end most things would naturally balance out.