Incentivize More People to Queue for Leveling Dungeons

[Sated]

Why would they add extra incentives for premades?

For the reasons I gave mainly: to promote community. This wouldn't be for roulettes anyway, the OP was talking about the leveling dungeons in ShB, which people don't queue for very often, probably because of Trusts. Roulettes already have plenty of incentive for everyone.

But honestly the best approach for this specific problem would probably be an "Adventurer in need" buff for specific dungeons or level ranges. But that probably fluctuates way too much to be reliable or useful. Even without a buff or incentive, forming a party of friends to do it is the best way, it's just not something everyone has thought to do because playing solo is so easy until you get hit with a minor inconvenience like longer queue times.