The number of pirated copies doesn't translate to missed sales.
Someone playing/watching/listening to something for free doesn't mean they would still do it if they had to pay for it.
One reason anti piracy companies make a living is because companies that buy it see concrete increases in revenue as a result. It may not be every pirate who converts to a customer but DRM solutions are priced to be below the expected additional revenue. And it's not always cheap.
It’s certainly not a 1:1 loss, but it’s also not zero