You can also paste that into the search of any lemmy instance to find it, if they mirrored it

Yes, this works. But I don’t understand how. The question is - will it work, if remote instance went down?

«Your original url is right there in the path if it were to go down» But how it’s supposed to help one, to see the original URL? It will help only if the content is archived in some way. If remote lemmy server will go down. Then content will became unavailable, even If I install a local copy of that redirecting engine.

it give the resulting link as https://lemmyverse.link/xn--e1aghfa.xn--e1aqbccjfc.xn--p1acf/post/15 so the lemmyverse.link website is the single point of failure. It goes against the idea of federation.