You are aware that it doesn't have to be the main team that port the game to older consoles and porting the game to older console can all be out source. Also, If devs support older consoles they will be able to sell much more of their game at the same price regardless of which console. So, I don't think any development studios would complain about making their game available to more potential buyers. The switch from one generation to another is actually pretty disruptive for development studios where you go from a very large install base to much smaller one. Especially for 3rd party studios that need to carve an audience for their game. 

This is reverse Xbox one X issue, where every one believed that no devs would scale their game to Xbox one X settings since PS4/PS4 Pro is the market leader. But, they were wrong all of the game this gen played best on Xbox one X and most game where enhanced for the Xbox one X. 

Microsoft plan is to give consumer the option to play at 720P-900P on (OG Xbox), 1080p-4k (XBox one X) or 4K/60fps (Xbox Series X) in the next two years. If you simply don't have the money to upgrade to next gen consoles or kid that parents don't want to pay for a next gen consoles. There, going to be so many people still buying on the older consoles for the next two years. No one left behind is actually a consumer friendly move going forward. Beside if the rumors are to be believe all of the next gen games will be run and look best on Xbox Series X. Xbox Series X will set the benchmark for next games for both 1st & 3rd Parties games. 

The games won't be built for the Series X and then torn down to work on the XBO.  They will be made to run on the XBO, then put on the Series X.  This is how cross-gen ports are done. Just look at AC:BF and BF4.  They share the same geometry for characters and environments between gens.  The next gen games do have a higher resolution and some textures are improved (not all), and there are a few extra effects, maybe extra foliage.  And no one is saying they look bad by any stretch, but it is not the night and day comparison that we see with, say, Infamous:SS and Infamous 2. 

They can't build this incredible game on the Series X, then easily strip it down to work on the XBO.  There's no guarantee it would work on a much weaker CPU/GPU before you have stripped the game to barely recognizable, read not a likely purchase.  Maybe if it was more like a Series X to a Lockart difference, they could.  But, the systems are miles apart.  

The only other solution is if they got a 2nd studio to work on the XBO version.  But after MS spent all that money buying studios, and more than likely getting moneyhated exclusives for next gen, and wanting to pump out a game every quarter, I highly doubt they want to pump even more money out renting studios to make seperate versions of all their games for the next 2 years.

True. Gen 9 also have the advantage over gen 8 in terms of B/C. For example, Xbox One owner can sell his console to upgrade to Xbox Series X without any hesitation because he knows that all his library will be there on a new console. In 2013, it was hard to justify trading in 360 for Xbox One because you would instantly lose access to your games.

Agree about Stadia and phones. But disagree about PC stores. It doesn't seem like MS thinks about them as a threat especially when they put their games on Steam.

From your scenario your consumer actually only care about graphic and performance, why would would they want to play all their 3rd party games on the inferior PS5. Xbox series X first party will run at resolution, frame rate and performance that can't be match by PS5. The limitation of how good a game look on consoles is the hardware. Your argument that 1st party game will look better on inferior PS5 hardware compare to Xbox Series X just doesn't make sense.

I still think Sony need to walk a fine line because I doubt they will entirely drop PS4/PS4 Pro support, you know that 3rd party will still support the older console after PS5 release. We know that Sony studios are all making games targeting the PS5, but all of these game can be ported to their older consoles. Remains to be seen what Sony will do for owner of older gen that haven't upgrade. 

Does power even matter Nintendo Switch is proof that it doesn't, really the next gen is going to pin Sony exclusive against Microsoft exclusives all of which can be obtain for much cheaper on Microsoft console console due to gamepass. Do you want an inferior PS5 at $399 where you have to buy all the exclusives or a superior Xbox Series X at $499 where all the exclusives come included with gamepass. 

Not everything is scalable, though. The massive jump in CPU and storage speed should allow for new experiences that can't be done on current gen consoles. Especially if we are talking about level design (that's supposed to take a massive jump in scale because of SSD), ai, physics etc. The truth is that cross gen titles usually aren't as impressive as the games that skip previous gen consoles. It simply has to do with them running on new engines that allow for things not possible on previous gen hardware.   

Oh, man, you got the detailed specs of both machines?  Do share.

I don't know what industry you work in but that not how game development work. Game are develop for target specs and graphic & performance can be scaled down to port on weaker consoles. Just think about all the recent port to the Nintendo Switch. They can strip enhancement layers by layers in order to work on weaker consoles. 

It's funny because your clearly wrong and striping down is exactly what they do. Guess what current gen and Nintendo Switch system are miles apart yet game can be ported to the nintendo Switch.

https://www.youtube.com/watch?v=RqTaot5V9B8

And the ports for Switch usually come months/years after the original games when we are talking AAA games.  They have the time and resources to fine tune the game to work on the Switch.  The games we are talking about are, more than likely, going to be launching the exact same week.  They won't be given that extra time, especially with the game every quarter MS is aiming for.  Again, look at the cross-gen games that launched this gen.

Also, the Switch is a pretty capable HH, especially when docked.  The CPU is pretty capable when compared to the PS4/XBO, as the Jaguar cores aren't anything special.  And the GPU in the XBO is probably something like 3x the power of the Switch's.  When talking XBO vs XBSX, we're talking about a huge leap.  The Ryzen cores offer a gigantic leap over the Jaguar ones.  And the GPU has already been stated to be more than 8x the power of the one in the XBO.  Simply scaling things down isn't going to be an easy task.  Maybe even impossible.  That's why cross-gen usually start with the lowest common denominator, unless built by a completely different team.

Yeah you're right, I took it as first 2 years of XBX rather than the 2 years following his statement.

Well everything is rumored and speculation except:

Microsoft quote: The new Xbox Series X. Fastest and most powerful.   

Sony --> Jim Ryan was quoted last month about their desire to move PS4 players to PS5 "at a scale and pace we've never delivered on before".

He went on to say "When we look at this transition and the ambition to do things at a scale and pace that we haven't seen, we have to look at ourselves and make certain changes."

Every thing else people might say is clearly rumors and speculation except for these quotes. The only thing we know for sure is that Xbox Series X will be more powerful and will most certainly cost more.