It's early to say. We're only about six months in. But I'm here anyway, so I'll bite.
I'd say 105 million, barely passing the PS1. I don't see really any way it sells below 95-100 million and almost no way it sells above 120-125 million.
I know it's just about the fastest-selling video game hardware ever (at least in the Americas), but that doesn't mean it will be in the top 3-5 best-selling pieces of hardware ever. The video game hardware market seems to be stabilizing, and will probably start shrinking in the next 5 years or so.
Given Sony's stupid decisions and the growing amount of PC gamers, I don't think PS5 will match the PS4 in lifetime sales.
Lifetime Sales Predictions
Switch: 151 million (was 73, then 96, then 113 million, then 125 million, then 144 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 57 million (was 60 million, then 67 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
