Quite a fantastic list. I recommend Spider-Man Remastered, then Ratchet & Clank rift apart, then Miles Morales. All super easy platinums and a lot of fun. Insomniac games are so very, very fun. 

Demon's Souls is up there, too, but I wouldn't make that your first PS5 game unless you're already a fan of Dark souls. 

1. Astro's Playroom
2. R&C Rift Apart
3. whatever

Yeah this. Astro is a short game but sweet game (only a few hours long) and something people should try it when they boot up their PS5's. R&C is a good shout.. then move onto the more meaty stuff. Maybe break up the open world games with action/roguelike in between so you don't get burnout from those games.

I would third this option :)

Personally I think you can skip Miles Morales completely if you already played the previous spiderman game and you not a crazy spidey fan. Also Demons Souls is great to look at, but at its core its the same game as what it was on PS3 - you realize this about an hour in. Definitely worth playing again but perhaps leave for last.

Then between Deathloop, Returnal and Ghost of Tsushima I would say pick the genre you like best? 

Did you not own a Playstation system before?  I was grinning ear to ear the entire play through of Astro's Playroom with all the call backs of every Playstation system.  Short but sweet and one of the best uses of controller, the feeling of shooting that bow, walking through the mud, and so many other haptic feedbacks are great.

I would play Astro first,after you beat that Mile Morales is short but fantastic.  After that I would actually go Deathloop.  Whenever I saw a preview for the game I thought it looked terrible and I didn't like roguelike games.  When the 10/10 reviews started dropping I started looking into it but decided against it with all the negative reviews online saying it was over-rated.  It was on sale for $25 on Black Friday and I bought it thinking I may never play it and just add it into my backlog.  For some reason I started playing it, and almost quit multiple times in the first 2 hours frustrated that I wasn't making any progress and kept getting slaughtered when a big group of enemies spotted me.  But once I got to a certain point and I stared learning about all the enemies things stared clicking and it became one of my favorite game of this console generation. 

1.- Ghost of Tsushi
2.- Returnal
3.- Ratchet and Clank
4.- Deathloop
5.- Miles Morales
6.- Demon Souls

This is how I'd do it. I agree with the guy that mentioned open-word exhaustion, so keep Miles Morales and Ghosts apart and im putting Ratchet and Clank between Deathloop and Returnal just to have a break from the serious tone of those 2 with a really fun and casual game.
The reason Demon Souls is last is just because its vastly superior to all other games in that list, so leave it last to not overshadow the other experiences.