[Crinus]

The last time there was a real UI and UX consistency was with Windows 2000 (or ME, if you want to stay on the consumer side). With Windows XP Microsoft introduced themeable controls but instead of making them available to all applications, they used an opt-in mechanism (based on special EXE resources or manifest files) so even nowadays unless you use that mechanism you get the Win2K era of controls.

Even then, with Windows 7 most things were consistent and if you really cared about consistency even with non-themed apps you could always switch to Windows Classic theme (which i always did, not so much because of consistency but also because i just like that theme :-P).

Since Windows 8 with the introduction of Metro/UWP/WinUI/WinWhateverNext consistency was thrown out of the Window, without even trying to pretend otherwise (it isn't a coincidence that the UI guidelines for desktop applications in Microsoft's site still use the Win7 theme).