Hypothetically if there were no shortages of any platform, it seems that 9th gen hardware demand is so great that Xbox One and PS4 was have saw a massive decline regardless of any realistic price drop.

Heck, its almost hard to believe Series S could be $199 in the future. Its just not a price point they aim for anymore.

Guess you are with poor information.

GPU market is dead as you say, had to buy a pre-build just to get a 3070 (a nice noctua/asus one). Giving my brother some of the parts, I'll have to wait for some DDR5.

My Amazon (US) is showing delivery early January if I ordered either sku of the OLED today (posted elsewhere in this thread).  I've been in Targets and Best Buys recently and never see them on shelves.  The websites are stating that some stores in my area have them.  I just haven't seen any in the wild recently (not that I'm actively looking for one, since I have a Switch already, but I do notice the empty case display while looking at the games aisle).  In any event, the Switch has been on the market since 2017, and has sold to 97 million consumers already.  On any given day, there would be 82 million less people looking for one than a potential PS5 customer.  So, you would expect the Switch to have plentiful stock everywhere.  That it's not in some places, like the major metropolitan area I live in, shows a combination of Nintendo also struggling with the chip shortage, and the device remaining in high demand over 4 years after release.  I think that sometimes gets taken for granted when comparing Switch stock to devices that just began selling 1 year ago.

I'm from Brazil and I can't remember the last time Switch was out of stock here 

Series S was readily available for months, but since last month I couldn't find them anymore on Amazon

Series X and PS5 though... I've never saw any stock for them 

The PS4 versions are catering for the existing PS4 gamers not to worried about new ones.

Very early in the PS5's history they ended certain Japanese made PS4 models and moved there Japanese PS4 assembly lines that while not the biggest in volume are Sony's and apparently the fastest available anywhere being fully robotic and taking just 30 seconds to fully assembled a console from start to finish with a line just 20 metres long with the only human involvement occurring at the end of the line with post assembly packaging that takes another 30 seconds.

Incidentally those facilities were initially created for the PS1 and now with the PS5 being assembled there they have now assembled every gen home console .

Yeah, PlayStation seems to be hurting the most when it comes to stock shortages. I see Switch and Series S readily available on pretty much every major online and brick and mortar retail store. As far as I can tell PS5, Series X, and of course the RTX 3000 series cards are still very hard to get ahold of.

Even if MS can't buy more wafer allocation:

MS can just notify TSMC that they want less XBSX wafers made, and more XBSS. This would allow MS to make way more (XBSS) dies overall.

MS very well may have already made that decision leading up to the holidays, to make sure they had as much stock available as possible.

Having XBSS be reasonably available on the shelves is better than having extreme limited availability for both XBSS and XBSX.

SNY can't do squat about PS5 chips because there is only one chip design. All they can try to do is buy more wafer allocation, if they can.

PS4 chips are made on a different node, so it doesn't impact PS5 chip production at all.

Not sure about the assembly line though. Less PS4's could mean more PS5's, maybe.

I still haven't seen a PS5 at a regular store yet. Only a few for double or close-to-double the SRP at second-hand stores. It's crazy.