In my research, it seems like the combined cost of 2 separate one-way tickets is almost always more expensive than round-trip tickets for the same destinations. Just curious if this rule is true across the board? Does this vary based on location? What circumstances would a one-way ticket be cheaper than a RT ticket and when would it be worth it to fly one way rather than RT? Any info that can be provided here would be helpful.

Asking because I assume most YOLO point redemptions for biz class / 1st are one-way tix, so just curious how to get the most bang for my buck / points with upcoming travel next year. Thanks.