I was under the impression that Quince's business model is such that all different items are differently designed and manufactured -- so fit would vary from item to item.
It's a platform for factory direct to consumer more than a fashion house.
So every item has to be judged on its own merit, there's no overarching theme of tend to fit bigger / smaller etc. The common theme is cheap.
Some of their items has a following for sure, like the cotton fisherman sweater which I have and like a lot.
I also have the SuperSoft Fleece Hoodie which has a wonderful handfeel but difficult to care for if you need to wash it a lot -- I would not use the dryer b/c of the synthetic content that makes it sooo soft. (The lighter color shows less dirt.) That said I would wear this every day every where if i could.
https://www.quince.com/women/supersoft-fleece-pullover-hoodie