It's actually even more nuanced than that. Someone might have a fixed budget that they're willing to spend each month on games. It doesn't matter what it is, just that it's relatively small. Also, they may not be buying games every month, but they will never spend more than that in a single month. If with that budget they can buy a very small number of games (maybe not even one!), more often than not they will not take the chance with any games and will simply try to pirate them. Is that a sale lost to piracy or not? It's hard to say, because they might or might not have purchased a game if it was impossible to pirate; it depends on whether it fits in their budget.

I really think the reason Steam pretty much solved piracy on the PC is because of the expectation of timed discounts. If right now a game is just outside your budget, you know that 6-12 months from now you'll be able to buy it at a significant discount, so if you're patient you don't need to bother with pirating it and you can just wait. Now, some people will still pirate just to be able to play immediately, but piracy is nowhere near as rampant as it used to be on PC. If Nintendo implemented similar policies on its stores (as opposed to trying to sell 30-year-old games for $5) it could solve piracy on its platforms in a day, without resorting to this cat and mouse game.