I confess I wasn't up to speed with the VAT registration threshold but it seems to me the figure of £82 k represents a good income by any standards.
Naturally expenses do differ. And there's bugger all in the way of VATable costs that a sex worker would incur except possibly working hotels for 'notional incalls'.
So it seems to me that a WG would be better off taking a holiday were her gross income to approach the registration threshold.
Tax people used to use the expression 'pure income profit' to describe items of income with extremely low if any related costs. In the present case the 'pure' makes one laugh. (I digress slightly)
Imagine a fifth of your income going off in Vat. It doesn't bear thinking about. It is, however, vital to pay your income tax and NI.