@Datas_Cat_Spot
Who was "better utilized" is a hard question in my view, but I think it's clear that Quark was a more fully developed character.
Guinan appeared seldom but always gave insight to characters when they most needed it. She was enigmatic, and cool, but not very fleshed out.
Quark was more realized as a character - more complex, more highs and lows, more emotions. I didn't like him much, but he was more "interesting" to watch.
You’ve hit on a good point there, Guinan always felt to me like a deus ex machina in the stories. It feels like when the writers don’t know how to resolve something, they just have a character go to Guinan and resolve whatever it is they were struggling with.
It also feels like they really didn’t know what to do with the character. Whoopie’s availability didn’t help with that, since she had only a very limited shooting time. Sometimes they made it seem like Picard and her go way back, but then she didn’t play any significant role as far as we know. And there were plenty of times where they would have been far apart for super long. They also want to make her an enigma, not really knowing her age or limits, with vague hints to her father and Q exclaiming she has powers. But nothing ever comes of this. And if Picard and her go way back, surely he would know about some of this stuff? But he never does it seems like.
Her whole back story is full of holes and the character makes no sense. But that’s common with Star Trek characters.
It feels like throwaway lines that get tossed around to make the character feel more than it is, but it’s completely hollow and ultimately comes to nothing.
It’s a shame, because I like the idea of Guinan, but story wise the character simply wasn’t very good and not utilized very well.