We're all victims of economic coercion. Very few would willingly work service or clerical jobs if they didn't need to.
If that's your rubrik, then whatever your opinion of Johns is, it should consistently be applied to anyone who ever buys any product or uses any service.
We all work because we need to get paid to survive. Knowing that, how do you believe those who choose for that work to be sex work should be treated?
Not in the UK, where the meme is set. NHS hospital administrators don't get a cut of any money because there is no money.