I think at the time there were some technical limitations, GTA IV too was a poor port to PC as far as I know. However, with GTAV it changed so I'd think a PC port should be in the cards.
The original RDR is still one of the best games I've ever played, acually that is the only game I miss from my old PS3 times.
As about other games, especially as I uninstalled Elite after almost four years.
I bought AC Origins, that is the only 2d game that makes use of my 1080ti and... wow, this game is a proper eye candy! Many say Black Flag is the definitive AC, but I hate the sailing mechanics and it feels like a remastered PS3 game, especially compared to Origins. I'm looking forward playing it through, and then picking up Odyssey as well!
I bought American Truck Simulator, but graphics in VR are kindeóa underwhelming. Otherwise it is a nice game unless my trailer gets stuck.
Mutant Year Zero is still discounted and heavily contemplating picking it up now.
And yeah, otherwise I'm still playing World of Warships.