Qt runtime installer or dependency system for Windows

It would be very useful to provide a "runtime only" installer of shared Qt libraries for Windows.

The are many open source Qt applications and tools that depend on dynamic libraries. For Windows all application must add their own copy or subset.
For example one application has a compressed size of 3 MB (executable and program data). To run the program on windows plattforms you have to add arround 10 MB of compressed Qt and compiler runtime libraries.
If the user installs two or more independent Qt application, not only the download overhead increases, but also the disk usage for each copy of the Qt runtime libraries. For each independent program approx. 50 MB uncompress dynamic libraries are added as duplicates to the disks.

If a global runtime installer and integrated solution for all qt versions is to complicated to implement or to maintain
(i doubt that other frameworks like Java has one):

One simple solution is to create a package of the Qt runtime libraries for each Qt version (... and graphic stack or compiler?). That package registrates his own install location to all Qt applications, either by modification of system PATH variable or a more flexible script / starter enviroment setup.

In this way no developer/packager has to worry about adding Qt libraries by him self. It works for Java, why Qt sucks basic support for that or any other solution? Maybe Qt lost focus in the past commercial driven era. I would appreciate any progress on this topic.