If Sony and Microsoft do good business, there is no reason both consoles can't make it to 100 million users before PS5 and XB4 arrive in 2022 -2024. Microsoft just needs to continue to push XBO closer and closer to Windows to the point where it is basically a PC at 2X $/performance compaired to other mass consumer PCs. Sony needs to expand the PS4 hardware to additional form factors, to stay competitive with Google, Apple, and Microsoft. Both companies need to release one more revision to the current consoles around 2019 - 2020 with 10 - 12TFLOPS, 16 - 24GB RAM, and SSD.

If they do the above, they will both easily sell well over 100m units, and create massive momentum behind the console industry.

So, doing some math, and there's very little chance the Xbox One makes it.

Here's why.

As of 2/11/17 the gap between the Xbox One and 3DS is 35,332,237. If the 3DS never sold a single unit past that week the Xbox One would have to sell 9 million units a year for nearly 4 years. Mind you, the Xbox One has NEVER sold 9 million units in a year, and the 3DS is going to keep selling.

Your predictions are always insane, do you know that?

PS4 basically outsold everything this gen and wrote history the day it launched.

XB1 may come close but I don't think it will catch it, assuming Scorpio ends up being tied into this gen.

Considering 3DS will continue to sell, and with the 2:1 sales for PS4 remaining fairly steady, and probably won't change all that much with Scorpio, PS4 would need to sell around 130 mil units for XB1 to reach 65 mil. I can see PS4 reaching 100 mil, but not 130 mil, which puts XB1 around 50 mil, give or take.

I always predict on Sony, Microsoft, and Nintendo doing the best most profitable, and wide spread thing they can do to grow their business. If they decide to stunt their own growth, that is beyond my control. I just prefer to be an optimist, and believe they will not continue to make the same mistakes they have in the past. 

It is not far fetched to think consoles can be some of the biggest consumer products in the world. All it takes is the right shift in mindset, and PS4 and XBO could easily become as big as smartphones. If the platform holders can continue to expand their offerings, and deliver an all around product that catches the mainstream, they will be off to the races. 

PS4, easily. XBO, most likely not.