McCartney and Swift ‘exploit’ tons of people as well. They might flagship their music artist operation themselves and kind of ‘be’ the product (or rather the brand), but there are lots and lots of people involved to make tours and shows possible, recording, production and especially distribution of music and merch involves labour as well.
In addition to that: I don’t think they store all that money on a nice little heap in their backyard. It usually gets invested into some sorts of corporations, be it through the stock market, where it will accrue revenue, that comes as the result of more exploitation.
That being said: the term ‘exploitation’ carries a much more negative connotation than would be beneficial for the conversation. It’s concept of marxist economics, and the term ‘Ausbeutung’ = exploitation was used by Marx himself to describe how capitalists benefit from the surplus that workers produce. I like the term ‘reaping the surplus’ better because it doesn’t carry as much of a negative connotation. The criticism of capitalism shouldn’t barely rely on the fact that surplus is being taken away from the workers, but from the consequences to society and the political system that inevitably follow when that wealth is concentrated in the hands of a minority.