"DLL hell" doesn't have anything to do with the built-in GUI API calls. The part of the API that pertains to the GUI is built-in, standard, and has been since the 90's. I can take an application written today and run it on Windows XP-10 and it will work as long as I take care to not use any API calls that are specific to later versions of Windows (very few for most apps).
If you want to criticize the GUI aspect of Windows, you should target the lack of any standard modern GUI API calls that don't involve using Direct2D or GDI+ (by modern, I mean full support for transparency and anti-aliasing, among other things). The old API, plain GDI, was standard and well-understood, whereas the newer improvements are completely different types of layers built on top of GDI. That's the real mess.
If you want to criticize the GUI aspect of Windows, you should target the lack of any standard modern GUI API calls that don't involve using Direct2D or GDI+ (by modern, I mean full support for transparency and anti-aliasing, among other things). The old API, plain GDI, was standard and well-understood, whereas the newer improvements are completely different types of layers built on top of GDI. That's the real mess.