(I am surprised, why so many people downvoted this)
Well, we see that many many posts include 3rd party links (recommendations, tutorials, typical text content and etc...).
Then the post may get high votes, but after 1-2 year, the link, mentioned in that post, may be deleted.. So, we don't know what there happened..
So, every 3rd party link should be automatically followed with "LAST VERSION" (or something else) comment:
OR that archived link should be attached in the bottom of the post, like
3rd party links backup, used in this post: 1) .... 2) ....
and that last version, should be the link to Google Cached (or archive.org) of that page... (Invent anything you want, I am just giving google cache as an example! If you have better choice, then tell me, if not, then stop downvoting!)
So, We will save many helpful posts from recycling.
P.S. To the people who downvoted - I will say that there are thousands of posts based on 3rd party links (and actually, all those posts are very useful - thanks to authors). So, we will never avoid 3rd party links, and the content (written there) is essential! Often, we can't paste the content of 3rd party links directly here, it is not convenient. At least, the archive will last a bit longer, so it is better, than nothing. And if the archive page will be removed too from google, then ok, nothing disaster is that.