As I said, once again, I'll bring Hogwarts Legacy into the mix:

PS5 has several gfx modes, in highest one it runs @30fps. Some things (like water) in Switch version look quite bad (in what is otherwise quite descent port), but bottom line is that if publishers are willing, and think that it will make them money (which WB obviously did and it had), they will make a port.
If they were capable of making Switch ports, I doubt, technically, they will have much problems making ports for Switch 2.

I suspect 10th Gen PS/XB will have hardware that will be very Ray Tracing oriented, and that there might be no non-RT versions of games by that time - we're talking several years into 10th Gen, after all cross-gen titles are released and games are only made for 10th Gen. That is something I can see being very hard to port to Switch 2, but by that time (I'm thinking 2030-31), we'll probably have Switch 3.

It is a fair point and I can't disagree.  And this is where I think Nintendo's porting studio could be really impactful.  And honestly, ps4 games still look and play great.  GoW 2018, sure it isn't Black Myth, but it still is stunning.  

Personally, I am not worried about RT, at least not real RT.  Real RT damn near breaks my 4090.  Consoles are not doing real RT anytime soon.  

Where there's a will, there's a way; even beyond ports like Hogwarts Legacy on the current Switch, there's a long history of games being crammed into hardware far weaker than they were designed for if the publisher decides to make the effort; Doom on SNES, the 7th gen COD games on Wii, Doom 3 and Half-Life 2 on original Xbox, etc.

More than hardware power, it comes down to how much effort and resources the publisher is willing to invest to make it happen; after the enormous success of the Switch, third parties will likely be approaching the successor with a lot more enthusiasm than they initially did the Switch.

4090 is very fine card. But I think by the time 10th Gen PS/XB release, we' be into nVidia's 60, or maybe even 70 generation (and AMD/Intel equivalents) - I fully expect those consoles to be built around path-tracing.

Unless completely new trend comes along and fundamentally changes everything (AI generates playable DOOM without any engine):

I hope you are right, because real RT is crazy impressive.  It looks just mind blowing.  I just don't use it often because I drop from 120 fps locked to 40-60 fps real quick.  But you are right, it will get better with newer cards.  

I don't really bother with Ray Tracing, too much hit on performance for what are often minuscule visual improvements over only rasterized game, but Path Tracing, done properly, can really change how the game looks.

But that part has always seemingly been the main issue. The extra development that goes into making the games function in an acceptable way. If it's just a matter of "turning down sliders" then there should be no problem. Eiyuden Chronicles developer cited the reason for a Switch port being difficult is that the different coding language essentially means they have to re-code the entire game. Presumably its a mix of coding and performance adjustments that turned third party publishers off. Because Switch 2 should still be ARM based. But perhaps there are better tools today for translating the code.

When it comes to performance balancing, Switch 2 should be in a better position than Switch 1 was because there are tools and shortcuts to help with that today, such as DLSS.

I think Switch 2 will be getting vast majority of third party games. Of course DLSS will be doing a lot to save image quality, and 12 GB of RAM will be plenty to make sure games don't run out of memory.

I actually think 12 gb is a bit too low.  Steam Deck is 16 gb.  Rog Ally X is 24 gb.  People point out GPUs that are 8 to 12 gb, but computers also have additional system ram (usually 16-32 gb), and the vram is way higher in memory bandwidth (3050 is 2x what the switch 2 will be + system ram).  The series S is often highlighted as being 10 gb, but comparative to the Switch 2, it has literally 2x the memory bandwidth, in a broad/generic/illustrative way the Series S versus Switch 2 is 20 gb versus 12 gb.  

I'm rambling a bit, but 12 gb is meh.  I am hoping the rumors are wrong and it is 16 gb.  

Series S only has 8 GB for games, Switch 2 will have at least 10 GB for games (2 GB for system) it will be enough for sure. 16 GB sounds way too optimistic.