Finished RDR2 over the past few days. Amazing game, albeit it with a few of the end game gangs feeling like reskins (skinners/Murfrees are essentially the same.) but I have absolutely no desire to keep playing after finishing, half because after completing it you don't want to besmirch the ending, everyone's redeemed and John Marston's setup for a nice life, for a few years, can't send him out nicking horses and torching ranchers alive for not being happy to see him.
Tempted to replay RDR now as well to complete the story all the way through now that has a bit more sting to it.
RDR3 would presumably be another prequel.