It is a very bad idea to call this kind of corruption "fade" or "wear out". Furthermore, what you write is so general that it's true by definition but carries virtually no information.
The sun will destroy earth in a few billion years and the universe will presumly collapse somewhen.

If you are that easy with throwing big numbers, please stay away from them. What you are doing is not arguing.

I see one way how Microsoft Windows would really incrementally corrupt the whole disk: Excessive defragmentation. If you do not use ECC RAM and most PCs don't, there's of course a chance that data is corrupt in transit.

Data in disk sectors doesn't "fade" either. Either the sector can be read or it cannot be read which causes a failure. There's no fuzzy state in-between that would justify a word like "fade". You can take it for granted that a harddisk will fail completely very soon after you notice some read or write errors. These are also hard errors, not something the OS can miss.

However, please look at the initial question resp. problem. The person complained that his computer gets very slow after some months and a fresh installation fixes this. This is a typical Windos problem which is caused by a bloated registry, disk fragmentation and dubious software running in the background which was installed as a gimmick or extra along with other software.

Suddenly the topic changes to data that seems to "wear out" or "fade". Keep in mind that he was initially also talking about a 6 months cycle. You see, there are two topics with nothing in common mixed into one.