Basically, just as testing recovery is part of a backup strategy, testing the usefulness of the “saved” information ought to be part of any “saving” strategy.
Edit: You can try links posted to HN e.g. https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... or https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... and see if you can read any of them via the archives.
I've found the cdx search feature of archive.org incredibly helpful to quickly find functioning pages (status code 200) and to see all contents that has been captured under a certain domain or page. For example, you can make a query using Linus's google+ page as the URL parameter with an asterisk as a wildcard[2]. This allows you to see all the captured content from Linus's Google+ profile, including individual posts
1: https://web.archive.org/web/20190331095744/https://plus.goog...
2: https://web.archive.org/cdx/search/cdx?url=https://plus.goog...
It's great that the reality is not "nothing is visible" but rather "a bit is visible" — still, the archive just isn't very useful, compared to the impression from statements like "98.6% of profiles saved" etc. A little bit of forethought or testing its usability would have made a huge difference (some js code to expand posts and comments before saving the page, for instance, as some other archiving scripts at the time did, which I used to save the profiles of myself and some of my friends… didn't run it on popular public profiles thinking that ArchiveTeam would have likely covered it in their 98.6%, but it turns out they did not).
In the future, with the right assistance, I'm sure they could grab better archives in the limited time they have.
I still don't think that makes what they did save less useful or make it less admirable.
It would be like a library burning down and then telling the firefighters that the few scraps of books they managed to save are not useful. Why didn't they use tools needed to save the books better?
1. Re "In the future, with the right assistance…", they don't seem to be very open to assistance, as mentioned in another comment (https://news.ycombinator.com/item?id=38411567)
2. At the time they were saying things like 98% of content saved, which led one to believe they'd get to properly archiving some of the popular profiles at least, but it turns out everything is only very partial: in your analogy it's like the firefighters celebrating that they saved most of the books, but it turns out they got only the front cover of each book. (Which is great, and better than nothing! It's just… if they had made it easier to see what they were saving, maybe more people would have been able to help? Or would have saved the ones they particularly wanted?)
You simply have to click the link to the full post. To browse all archived direct posts, you can use this URL:
<https://web.archive.org/web/*/https://plus.google.com/%2BLin...>