It is a balance between required disk space, security permissions and comfort.
If each application is fully contained in its folder, it means that all relevant libraries need to be in that folder. If other applications use the same libraries, those will be repeatedly copied over.
Also, having all files in the same folder of the application means that temporary files have to be created there and as such these files need to have the permissions of the different users that access them. Also, imagine that two users share the same application folder: what if they setup different preferences?
This is one of the reasons you have "Current User" in the Registry, as well as, C:\Users\xxx\...
At the end it is a balance of how efficient you want to be in terms of not replicating the same files/folders over versus the commodity of uninstalling files.
With that said, don't think I am happy with Windows: install one Autodesk application and you will clutter the disk and the registry with thousands of files and entries. The only way to fully clean up your computer is actually to reinstall the whole operating system!
I own an iMac and a Macbook Air (both purchased second hand for little money, just to get familiar with OSX and the Apple way). It is true that you remove a software by basically dragging it into the trashcan. But boy, there are many other things that freak me out on this operating system. To start with, it is really a closed environment. If you get an older iMac like I did, an "early 2009" one, you will find that there are many applications you can no longer install! Most software needs to be purchased (even if it is for free) from the App Store. Here you find only the lastest version which more than often is not suitable for your OSX version (for no particular technical reason, btw.). But you won't be able to download an older version, either! Unless you have purchased it, which you can't, because the new version is not compatible. This is to me a borderline scam... And yes, I hacked a newer FW onto my iMac, despite it being "officially" not supported. I even hacked Bootcamp to install Windows 10 and the relevant drivers, despite it being listed as not compatible. So much for the Mac...
Back on topic, I am now more familiar with Windows 11. The rounded borders look nice and more modern. It really seems more responsive and faster. But I don't understand why Microsoft has still not managed to migrate the Control Panel to the new Settings Menu. That is totally inconsistent.
Also, I totally dislike that Windows tries to hide stuff from the user. Why are folders localized (C:\Users is shown in Portugese Windows as C:\Utilizadores when using Windows Explorer, but on the DOS shell it is C:\Users?
Why are some folders hidden (like ProgramData or AppData?
Why are some .Net apps installed in some strange remote folder within AppData?
Why do folders generate some hidden config files?
Why does Windows constantly change my folder containing my music library (just mp3 files in folders) as "Music Folder" instead of "General Folder", hence changing the way the files are listed?
The list goes on...
When I support my students on their laptops, most don't have a clue on how the most basic things work on their Windows installation. File extensions of known file types are hidden, ZIP archives are treated by Windows directly as if they were folders (as a result software won't open projects, because they have not been extracted - only the single file where the user double clicked on it).
If I am able to list a ton of annoyances for every day use of Windows, how come that Microsoft is not able to list them? They surely have smarter people than myself working there!
So my guess is that i am just dumb and all these "annoyances" are required to somehow maximise their profit.
Regards,
Vitor