Marxist Critique of Sex Work

I was listening to some podcast that was talking about Only Fans, sex work and emancipation, and it got me thinking... Perhaps there is a Marxist critique of sex work. The sketch of the argument is below. 

1) Our sexual capacities and practices are an integral part human nature, as men and women.

2) Because (1), a person’s sexual autonomy should be non-alienable because to alienate it is to destroy a person’s wholeness/integrity.

3) Work, within the capitalist mode of production, alienates the worker from his ability to fully determine their goals, actions, and production of their own labour.

4) Sex work is a form of work within the capitalist mode of production.

5) Sex work, like all work within the capitalist mode of production, alienates the sex worker, though sex work, by definition, involves one’s sexual capacities and practices.

6) Because of (5) and (2), sex work destroys a person’s wholeness/integrity.

So, if this is correct, then sex work should be discouraged - at least in a capitalist context. Additionally, promoting sex work as a part of a sex positive feminism entrenches a form of capitalist-sexuality wherein women place their bodies in the market. (This latter claim will have to be developed in the future).