if you are asking which one to play, it depends, but i'd say RDR2, GTA V is fun and all, but a bit outdated in my personal opinion, RDR2 offers a great game to dive into, with a great story and characters that just sticks with you long after your last save game.

again, it could be a personal preference, but i feel like the characters in GTA V are less thought through and more desperate trying to be funny, that's pretty much the entire game when it comes to characters, everything is trying too hard to be funny in a way that is just not funny (sure some things are hilarious, but that's maybe 15% of the game, the rest is just junk of desperate "funny" lines)

RDR2 also offers online like GTA V does, but if you are playing on PC, it dosnt really matter what game you choose, you will lose patience and find something else to spend time on, instead of trying to play a game you just bought and have it ruined by script kiddies and hackers.

i liked both games, probably spend same amount of time online in both games, but story mode, i completed RDR2 while GTA V just wasnt my thing and i left it at something like 60 - 70 % completed.

but there certainly is something to it when people say, RDR2 is more "slow" paced but has deeper story and is for the more mature audience and GTA V is more pubic and speaks to the under developed teenagers (sorry, not sorry, but it's funny cause it's true).