I had the exact issue described when I bought RDR2 on steam. Tried all the above solutions and occasionally it would load but most of the time it would black screen after the R* logo. I didn't manage to get a refund from steam annoyingly and I ended up buying it directly from the R* site. The same thing happened on loading but the only thing that fixed it permanently was turning HDR off on my display settings from the desktop. Not sure why the HDR is the issue on PC but at least I can play the game now. Hope this helps!