It is true that Switch sales are going to explode during the next few years, but it mostly won't be due to games that create new gamers like Wii Sports and Brain Age. Switch sales will explode, because it is Iwata's answer to Nintendo's philosophical/internal problems.
While the Wii was a huge financial success, it wasn't sustainable, because their developers didn't really want to make games for it. That was the Wii's biggest problem and why Nintendo seemed to stop supporting it so quickly. On the other hand, their developers wanted to make Gamecube style games, but the mainstream didn't want to buy the Gamecube. Also if the mainstream doesn't want the console, then third party companies won't support it either. So that was the Gamecube's main problem. What Nintendo really needed was a console that would sell games that their developers wanted to make and also still appeal to the mainstream.
Enter Switch. It's flagship games are the core type of games that their developers are comfortable making like Zelda: Botw, Mario Odyssey and Splatoon 2. At the same time, Nintendo's handhelds always appeal to the mainstream. Switch has internal appeal to their developers and external appeal to their customers. Switch will get lots of third party games, because Nintendo handhelds always get lots of third party games. In short, Switch uses all of the strength that Nintendo always has in the handheld market and brings that strength to the home market.
That is where the explosion of sales will come from: the home market. As the Switch's library grows and grows, the home market won't be able to resist coming over to Nintendo. They will "switch" from Sony to Nintendo. That was Iwata's plan all along, and I expect it will be successful even though he isn't around anymore to see how it will all play out.
curl-6 bet me that PS5 + X|S sales would reach 56m before year end 2023 and he was right.
My Bet With curl-6
My Threads:
Master Thread, Game of the Year/Decade
Switch Will Be #1 All Time
Zelda Will Outsell Mario (Achieved)
How Much Will MH Rise sell?
My Bet With Metallox