You say it's a silly point and proceed to explain how Demon Souls remake is a next gen experience although the game exists on the PS3. It has no 'next gen' features outside of better graphics which the PS4 could probably come close to replicating. Your main reason for enjoying the game seems to revolve around the fact you did not play it before. I guess anyone enjoying the updates to frame rate and resolution on other games those people also have not played do not count I guess. Not everyone has played everything. There is no clear definition of 'next gen'.
If a company is going to take the time to produce a game I'd simply prefer the God of War 2018 treatment. I have not seen anyone explain why that is not the superior way to remake a game over just a graphical face-lift. If Demon Souls had new gameplay mechanics and story it would easily avoid any comparison to what's being done with some back compatible titles. Games like Gears 5 and Forza 4 on the XSX look just as impressive and I don't believe MS charged for those updates.
If the content of the game is identical upping the resolution, adding HDR, doubling the frame rate, faster loading times, improved texture filtering and NOT making me pay for it was a major wow factor this gen so far. Things like quick resume, and smart delivery really improved the quality of life on a console. I'd love to see a platform holders resources go into making lots of games better not just one but different strokes for different folks.
Maybe you don't understand why Demon's Souls was remade.
It is one of the most important games in recent history, that's not even an exaggeration, since it created a new genre. It is often neglected and overlooked by Dark Souls, which improved on its predecessor on every facet.
But Demon's Souls was the more influential title and have just read that it even inspired the design of the PS4.
The title on PS3 wasn't experienced by many at all, to give a truthful remake is what fans craved and were given. Its nice that Sony listened.. hopefully they are listening now for the Silent Hill reboot/remake.
If it could have been done on the PS4 I'm sure it would been. Since it isn't there, it leads me to believe it wasn't possible. Unless have some proof?
Since super fast loading between deaths & travelling is making use of the SSD.
Assets, models and sound have been completely redone specifically for PS5, so streaming those in might be too much for the PS4 without some comprises.
I'm glad they didn't and developed it with only one SKU and console in mind as the results are fantastic. The 92 metacritic score suggests they have done a great job too.
On the Xbox side of things, yeh, Smart delivery has been useful with the last gen titles.
Dont personally use Quick Resume, as I have a habit of closing each game down.
But in a new console those features don't really excite me. I purchased next gen consoles to ultimately play new games and in Demon's Souls, it managed to stratch that itch.
For Xbox Series S/X to not have any launch titles, I get why Smart Delivery and Quick Resume has become more important. And seemingly in your case more important than actual next gen games.
Let's hope there are next gen games for both soon.