Is a worker earning £30,000 per year necessarily exploited? Are all workers automatically part of the proletariat?

In the M-C-M’ cycle of capital:

M-C: the bourgeoisie purchases labour power at the value of labour, and constant capital [v+c] C-M’: the worker labours and adds value to the raw materials used, which is then sold as a commodity for M’ [= s+c+v]

Exploitation happens when the labour time necessary to produce the value of labour power purchased in the M-C stage is smaller than the labour time previously purchased and then expended in production in the C-M’ stage. This is well known.

But what happens if the labour time necessary to produce the value of labour power is larger than the labour time purchased and then expended in production? Exploitation of the worker cannot happen. To give a concrete example, if the value of labour power in a certain context and for a certain period is 10 hours of labour time, and labour power is purchased but only 8 hours of labour time is expended, then instead of there being ‘surplus value’ from the point of view of the capitalist, there is actually ‘deficit value’ – the worker actually receives a ‘surplus value’ of 2 hours themselves. Value is transfered to the worker rather than extracted.

This situation might seem preposterous from an othodox marxist point of view, and Marx certainly never talked about it apart from as a temporary affair that would soon put the capitalists subject to it out of business. But modern imperialism, a preposterously degenerate stage of capitalist development, makes the historically abnormal become normal.

With imperialist nations and businesses moving surplus value accross borders on a gargantuan scale, it actually becomes possible for the capitalists in the imperialist nations to run businesses without extracting surplus value from their own nation’s workforce. The imperialist bourgeoisie can run a 'deficit value’ with regards to their own imperialist workforce because it is offset by the value drained from the periphery.

In fact, once we take a look at how crises in capitalism function, we can see that the imperialists running a 'deficit value’ with their own workforce is an integral tool for keeping modern imperialism afloat. If the imperialists didn’t run 'deficit value’, then modern capitalism-imperialism would suffer an unimaginable crisis of overproduction and underconsumption. Value produced needs to be realised (that is, finished commodities need to be bought), but without running a 'deficit value’ this could not happen at the necessary level. In general, the bourgeoisie of the core must seek to not exploit most of their own workforce, but instead exploit peripheral workers all the more to pay for their profit, the wages of all unproductive workers globally, and the wages of the unproductive “productive” core workers.