This revelation comes thanks to peerless research from our friends over at VGC, who have determined that the Switch has surpassed the Famicom in terms of time on the market before the arrival of a successor.
Switch launched on March 3rd, 2017, and it has now been 2,687 days since that date - the Famicom was on sale for 2,686 days before the arrival of its successor, the Super Famicom / SNES.
It's worth noting that this fact only applies to home consoles; the Game Boy was Nintendo's flagship handheld for a whopping 4,352 days before it made way for the Game Boy Advance.
You also have to take into account that this is only based on days from launch to the release of new, replacement hardware; as we all know, systems continue to get support even after their successor has been released.
We still don't know exactly when Switch's successor will arrive, but it should be soon.