reminded today of the importance of the internet archive when I wanted to show a friend the Pottermore article arguing that freeing slaves is bad but I couldn't access the Wayback Machine because the IA is down... luckily somebody backed it up on archive.ph (https://archive.ph/drNai) but there's a lot of stuff that isn't, & if the IA ever goes down for good, it'll be hard to prove things existed that were taken down, or be able to read them for yourself/show others so they can see for themselves...
it's not simply that we won't be able to read deleted things, but we won't be able to verify them or to give other people verification that it said what we claim/remembered it said... and people can claim that articles DID exist saying X but were deleted and we'd have no way of verifying it :\