I was playing through the MSQ until I reached a certain Trial.
I want to do it with my friends, but people have different schedules, so the plan was to do it during night time or on weekends.

In the meantime, we still want to do our daily roulette.
And for whatever luck, I got that Trial pops on my roulette.

Of course I could just abandon, but I was too flustered by the fact I got it popped on my roulette and telling the party that it's my first time, to the point I forgot abandon is even an option. (besides, it wasn't really prime time, so I might screw the rest of the players to wait/re-queue by abandoning)

I could think of other examples for how people could find this option useful, but I also understand there are arguments for how this option is unnecessary.

I just hope if the devs read this, they will consider adding an option to exclude unlocked but not yet completed contents from the Roulettes.