Dub has two big problems. 1. Unmaintained dub stuff.2. Let's say you need bindings to postgresql library and you will see dub pulling in numerous of libraries, which have nothing at all to do with postgresql. More like a framework stuff. This creates unneeded complexity, bloatware, dependency hell, maintainability, in my humble opinion. Dub should do one thing and do it good.
Feel free to elaborate.