Since 2013, Perma.cc has been providing researchers and law first firms the ability to provide URLs to online content that is archived permanently; somewhat similar to The Internet Archive, but on an as-needed basis. The idea here is to get rid of link-rot from "their" Internet:
Perma.cc will store the page [you provide] and give you a unique Perma Link - like perma.cc/ABCD-1234 - that you can use to direct readers to the preserved page.
However, the source link has to be "vested":
Links become permanent when they are “vested” by someone affiliated with a vesting organization, such as a journal or court. Perma.cc limits vesting privileges to help prevent abuse and to focus on solving the problem of link rot in academic and legal writing.
There may be some areas on Stack Exchange that fall under the umbrella of academics (not only Academia.SE) and possibly legal writing.
Would there be interest from Stack Exchange to invest in this idea and/or starting a discussion that may make use of this?
This is in a similar vein to Stack Exchange's investment in an IMGUR pro account, making image uploads "through a specific portal" remain available indefinitely.