In the end, RDR2 is a AAAA (aka AAA+) game, while AC Odyssey is a AAA game. The budget and man-hours that went into developing RDR2 are on a whole other level than the budget and man-hours spent on AC Odyssey.
Budget and time spent does not always dictate quality. There are ways to make a better AAA than Red Dead without spending nearly as much time on the game.
Zelda fans are the worst