[quietbritishjim]

The text below that example says that the .html ought not to be there. That's clearly not intended to be part of what that example is demonstrating, but I guess it's just there because they were going for real world examples.

The arbitrary path hierarchy is not so bad. Better than every URI just being https://domainname.com/meaninglesshash. You can also stick a short prefix in front, like https://domainname.com/v1/money/1998/etc, so that all documents created after a reorg can use a different prefix. If your reorg is so severe that there's no way to keep access to old documents under their old URI, even if it has its own prefix, it seem unlikely they'll be made available in any other location. In that context you can imagine the article is imploring you "please don't delete access to old documents".

Your remaining objections, for host name and access, boil down to "don't use URIs at all, and don't bother to avoid changing them". As I type this comment I'm starting to realise that was your whole point, but it was a bit buried alongside minor objections to this particular example. It's also perhaps a bit of an extreme point of view. Referencing a git hash alongside a URI is sensible, but on its own it's pretty useless, and many web pages won't have anything analogous.