If you look towards history, this question has been asked many times:

• In slave societies, if you abolish slavery, who will do the harvest / work in mines / construction?
• In feudal society, if you abolish serfdom, why wouldn't the serf just leave? How would the serf work to supply the Lord and the city with food and services?
• In capitalist society, why would anyone work without wages or profit incentive?

The reality is, when society changes, the material incentives for work also change. In slave society, the material incentive was violent coercion, in feudal society, the serf would be able to keep part of his work but would also be coerced through an oath to their Lord, in capitalism the worker is coerced through a wage and through the fear of unemployment.

In communist society, which now is only an idealized abstraction, society will have its own material incentives. But speaking of today, we do have blueprints for what could evolve in the next stage. We could all have a share on both in direct wage or in the capital accumulated, in case of cooperative enterprises. We could have an incentives based on goals and performance, as it happens in state owned companies. The wage system won't disappear overnight, but wage is not necessarily a problem if you don't have labor-capitalist social relations.