The way I understand dear imgui it tries to be first and foremost a quick and easy gui for debug and other simple interfaces. quire can do that as well, but I want it to be well suited for general applications. That's why quire allows you to build your own UI elements relatively easily. Either starting from the default elements, customizing and combining them, or even starting new elements from scratch.
I don't think it will be "superior" to dear imgui, but it will be different and better suited for some use cases.