I feel like this kind of thinking presupposes that people are naturally lazy leeches who won't put in work unless a sword is hanging over their head. How did people in hunter gatherer societies do their part without the incentive of per berry payment? This kind of reactionary thinking is sort of Thatcherite. The willingness to work or lack thereof is not immanent to human neurobiology. It is a product of the culture and society.

Regarding how the economy and supply chains will be organised, it is important to keep in mind classless communism is only expected in a very very advanced stage of societal development. This hard to foresee but not entirely pointless to ruminate about. Not being able to imagine a better world doesn't mean that a better world is not possible. If you take an example of a less fun job like garbage collection, there are various possibilies. It's possible that the technological advancements have made manual garbage collection obsolete. Or that maybe you are provided equipment that makes it safe, you work for 6 hours in a day and free for the rest to do as you please, not having to worry about rent, medical costs, paying your kid's tuition etc. Either way it won't be like manual scavenging in today's India.