Early to say, but I'll predict 60 million.
Xbox does fine enough in North America and Europe, but is a nonfactor in Japan. Xbox is also the least-focused on the hardware. They want you to play Xbox, but they could mean on Windows or other means. They're more into gaming services. Some people hype up the first-party studios they've acquired, but I don't think it will make a big enough difference for the Xbox Series to get close to the lifetime units of the Xbox 360.
Lifetime Sales Predictions
Switch: 161 million (was 73 million, then 96 million, then 113 million, then 125 million, then 144 million, then 151 million, then 156 million)
PS5: 122 million (was 105 million, then 115 million) Xbox Series X/S: 38 million (was 60 million, then 67 million, then 57 million. then 48 million. then 40 million)
Switch 2: 120 million (was 116 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima
