How can “they” fix what other people queue for?

“They” cannot. You pick an obscure extreme trial maybe 60% of players never unlocked and only 0.1% of the remaining would likely queue for, and only 1% of those have the fight knowledge to complete...

Put it in party finder unsync’d and then people will know you want it and might join you...

But in the random DF... that’s not going to pop on purpose.