Hmm, I actually think every successful console taps into multiple markets of gamers. Switch has the potential to tap into a few. But I don't know if Nintendo will do so. Also in the public image the Switch might look outdated as soon as PS5 and Scarlett release. That might cut the lifetime of Switch short. So I'm currently quite sure Switch will go past 50M devices, but still in the unclear if it goes on to 100M. We'll see.
Actualy Nintendo several times said they aiming Switch to be accept wide market (that why you have games like Zelda, Metroid, Doom...but also Kirby, Mario Party, Labo..), they even said they want Switch to be one device per person instead one device per house but also that with current price point that still isnt possible. Switch is not selling even now because its modern, it selling because great concept, games and marketing, and Switch will have all those things even after PS5/XB2 are out with difrence that Switch will than have much more affordable price point for mass market, probably around $200. Offcourse you are sure that Switch will pass 50m when at end of this year Switch will pass 30m and thats less than 2 years on market. :D With sales like this Switch will probably be around 50m with around 3 years on market.