The reason would be Xbox taking back some market share. It's only outpacing the PS4 a bit so far so it doing 10-20 million less lifetime is possible with a stronger competitor this time though I do think around 100m is the low end of what the PS5 could sell. It's also possible it still does a similar amount or even a tad better despite that but I do think the latter would require the console base to grow and with how stable it's been I don't think it would grow by that much if it did. I could see something like 60m/130m happening as well but I'd be surprised if the total reached 200m.

If you're indirectly replying to my post here I didn't say I expect the PS5 to only sell that much, I literally said the ratio staying the same was a big if. I think around 100m is the low end for what the PS5 can sell so I do agree it's unlikely.

I do expect PS5 momentum to collapse very similarly to the way the N64 did, especially outside of Europe.  In Europe, of course, the PS5 will continue to do fine for years.  However in the US it will probably peak next year.  Once Americans see that Microsoft is really trying again, and Gamepass is a pretty good deal if you like those kinds of games, then Americans will head for Gamepass/XBox.  In Japan and RoW, I expect PS5 to peak this year.  It won't be such a desirable item to scalp next year out of Japan, since scalpers will have the Switch OLED model instead.  

So much doom and gloom for the fastest-ever selling ever Playstation.

Someone insert the *Dude, I almost had you* meme from fast & furious.

Ps5 will be a massive success. Switch has already surpassed expectations by a whole bunch.

Both parties should be happy.

It is only selling because it is a 4k player.  

Depends, if it beat BF 2017, yes. If not, below 49k.

either way, it seems that Switch will do about 150-175k in Europe for OLED launch. 

The PS5 can easily outsell the PS4 if Sony isn't complacent. Finding a PS5 in stock right now is much harder than buying a PS4 was launch aligned. I bought a PS4 from Amazon with relative ease 10+ months or so in the last generation. If I wanted to buy a PS5 right now I'd have to follow social media accounts to find out about potential drops from different retailers. This is with a higher price point, $70 games, the Bethesda acquisition, a cheaper Series S model, GamePass & overall stronger competition that so many cited pre launch as obstacles for the PS5 to be as dominant as the PS4. Just look at how many expected the Series S to dominate out the gate compared to its current stock situation.

People underestimate Playstation's brand strength in ROTW territories, which according to VGChartz, Sony is the only platform holder to have multiple consoles (PS2 & PS4) sell more than 20+ Million in ROTW, as well as the only platform holder to sell more than 15+ Million (PSP) although the Switch could achieve this in a few years. Even a small anecdote like more females getting in the Playstation ecosystem, presenting another growth vector, potentially showing how female protagonists like Aloy/Ellie can attract and create mindshare towards the female demographic. China is also another major focus, where Sony projects the PS5 doubling the PS4's LTD sales, and its a region where Sony is looking to invest/strengthen ties as we see with China Hero Project or Genshin Impact (one of the most popular F2P/mobile games in China). Add in a slightly longer generation with price cuts and the PS5 could easily break through 130+ Million LTD.

I think the global pandemic last year renewed a lot of interest in people who used to game but fell out of the hobby. This will, IMO, increase the general ceiling of the console market & will benefit each platform holder.