I've only recently come around to thinking it will hit 110 million. There's a lot of reasons that it could not hit more than that. Lack of price cuts, lack of new software from Nintendo, production delays/complications, or somehow overall decrease in consumer interest. The lack of price cuts hasn't been a problem on Switch yet. But if we're going into 2022 or 2023 with Switch still at $300 and Switch Lite at $200, I think there will be a problem.

Lifetime Sales Predictions 

PS4: 130 mil (was 100 million) Xbox One: 55 mil (was 50 mil) Switch: 110 million (was 73, then 96 million)

3DS: 75.5 mil (was 73, then 77 million)

"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima