Well no, you asked if there are 100-120m people who want to play Nintendo games. I'm saying yes there are.
3DS was only moderately successful outside of Japan, this is not the case for Switch. Switch is doing significantly better than 3DS in America, Europe and especially Other regions.
For example, at their investor meeting last January Nintendo announced that Asia (not including Japan) made up 1.4% of 3DS sales while it makes up 7% of Switch sales.
That means that in almost 7 years 3DS sold 1.1 million in this region while Switch sold 2.25 million in under 2 years.
These regions have grown so much that Nintendo has decided to seperate Europe and Other into 2 separate regions in their quarterly reports (they used to be blocked together).
80 million may have been the saturation point for 3DS but it is not for Switch as it is a mainstream success in every region.
This is is very interesting and is more response to the question I was asking. Before you were simply talking about how many years of support a system gets and assuming that a Nintendo system with late life support will automatically perform far better than previous systems (which assumes there isn't a saturation point).
To clarify my first post which I worded awkwardly. Me asking whether there are 100-120m people interested in a Switch is not me saying I don't expect the Switch to pass 100m, i fee like it definitely will but naturally 5-10% of those sales will through people double dipping. Most people who I know who own a Switch lite already own a Switch and I expect at least another SKU coming from Nintendo. There also people who bought a new base Switch just for the improved battery life...
Regarding the PS4 we will have to see whether these other regions account for enough growth to enable Switch to do over 120m, I'm inclined to say no unless Nintendo manages to expand its reach in the major markets too. Maybe there already have but I think they've just tapped into their audience quicker and more efficiently then past systems as oppose to expanding it.