Earlier quoted context omitted.
I encountered rot today when I was trying to repair a set of speakers. I found the guide on some audiophile forum, step by step with pictures for every removed screw and multiple angles. Only the pictures were originally hosted on photobucket and since retroactively removed. Some reddit users are egregious about it, installing scripts that overwrite their comments after x amount of time, seemingly oblivious to the fa…
Rot may actually be useful by allowing out-dated, inaccurate, or useless information to be removed or fall into obscurity. Correct, useful, or noteworthy information is often re-posted and copied, leading to preservation.
There is value in archiving things beyond just relying on the small % of things that get actively reposted elsewhere. A good local caching solution of everything you've viewed on the web would be extremely useful for your personal reference, especially when sites frequently close and links die.
If you really wanted to fantasize you could seed your cached site data using bittorrent to maintain a common web archive with everyone on the internet, free from a reliance of one lumbering archival corporate entity that might disappear on the whim of a VC or shareholder, free from commercial profiteering practices, free from the ad men and anyone else who's job it is to pollute and dilute technology for profit, and firmly in the hands of the users of the internet.