It doesn't - it provides a perfectly equivalent platform.
In all cases, it will be the codecs registered with the OS that would be used - so the quality of the media cannot be better/worse.
Where this differs is from a developer perspective - you don't have to learn a non-standard UI API (XAML/WinForms/MFC/COM/ATL/Qt/Gtk/Swing/awt/whatever) or a language you're not familiar with (C#/C++/Java - pick any). But you can be sure that the experience will be precisely the same - no API hacks to achieve something specific, nothing at all.
What makes those platform APIs useful are all the tools they provide to simplify the creation of great, well-performing UIs that exceed the user's expectations.
