I can't speak for color management as I have no real experience with color calibration so I cannot say whether it is worse, equal, or better to macOS.
Yeah, it's definitively worse on Windows. Windows is the whole reason wide gamut monitors come with an sRGB emulation mode. And a lot of this sits on the fact that GDI+ itself is ancient and barely supports color management at all.
Meanwhile, Apple has been working to deprecate and close the holes that allow apps to avoid giving a real color profile to the OS when doing their own pixel work. Right now if you don't use profiles, it (rightly) assumes you probably meant sRGB, and will handle it correctly on wide gamut displays.
Regarding the mis-mash of different design philosophies that comes with evolution. A new OS supports a new technology but not everything can take advantage of it right out of the gate. Application developers need time to utilize it. Even the OS developer needs time to migrate supplied applications over, Apple is not immune.
I'm talking about Microsoft itself. They brought in "Metro" in Win 8, but have yet to fully embrace it after almost 8 years, instead you get a mix of new and old in system settings and other areas. Now the buzzword is "Fluent" and Microsoft's own use of the design language is spotty because they basically announced it to the world once they had the fully formed thought, and not when they had products lined up ready to go with it.
A fresh install of Windows 10 simply isn't consistent with itself. Sometimes you wind up with forward/back browser-like navigation (which itself is jarring because of how rarely it is used, and how Metro buttons basically refuse to call attention to themselves), other times you have modal dialogs. Sometimes, you have Metro, other times you have Win7, and you might occasionally run into Fluent.
Then there's the backwards support. Given Windows' strength in this area it is possible to run very old applications. Applications which may given the appearance of a mis-mash of technology. For example: One program I use, ACDsee version 3.1, is almost 20 years old. As it is an old application it has the old look and feel of contemporary Windows versions at the time of its release. Is this a mis-mash? Or should I upgrade to a later version which had a modern look to it?
Yeah, I wasn't even thinking about the third party apps. But generally, if you want a consistent experience out of third parties, the platform has to do some tending to the garden rather than let it run wild. It doesn't help that Microsoft basically has left devs to fend for themselves trying to modernize apps built on Win32/GDI+. They wanted them to use .NET, which effectively demands a re-write, good luck with that. Now there's UWP, but it's not a complete platform yet, despite existing for years.
TBH, my thoughts are that Microsoft shouldn't have tried to bring Metro to the desktop wholesale at all. Some things like tiles in the Start Menu (and a tablet mode for that start menu) in Win 10 are good choices. But Metro apps themselves much less so. It speaks a lot to the real difficulty of bringing a desktop OS to tablets and getting it right. And in a way, they are still paying for those choices, even in Win 10.
Ironically, despite getting slammed for picking Obj-C for MacOS X back in the early 00s, Apple has done so much better on the API front it's not even funny. Apple has always supported mixing old and new (C/C++ Carbon + Obj-C Cocoa, now Obj-C Cocoa + Swift Cocoa, PowerPC + Intel, 32-bit + 64-bit) in a way that gives developers time to adjust. Something I wish Microsoft did more of, and less "Here's this new thing, fully formed, and almost wholly incompatible with the old, and silo'd away from everything else" and then wonder why adoption rates suck for the new thing.
And yeah, I'm a developer, I've spent time on both platforms, and I actually like C#/.NET. And I can certainly get work done on Windows, and I've watched it evolve over the last couple decades. But it definitely isn't my favorite platform to use or develop on, for reasons mostly in Microsoft's control.