It's exaggerated alright, but Nintendo first-party titles very rarely go on sale and when they do, savings are lower than other manufacturers' first-party titles.

As an example, BotW is at around 35% discount a couple times a year on average (although it wasn't on sale at all for around two years, 2020-22).
In comparison, on Sony's side, Demon's Souls is at around 55% discount these days when it's on sale every couple months or so. And yes, that's technically a second-party title, but I feel it's more relevant to compare launch games in this instance.
Even Sony is becoming greedy with its own published games not getting huge sales like they used to.