Yes you save something that's mildly better than print-page-to-PDF. But it still misses things and the interactive stuff is very much part of 'exactly what I see'. Like, a random article with an interactive graph, for instance - like this recent HN hit https://ciechanow.ski/airfoil/

It's not that there aren't workarounds, it's that they are clunky and 'you can't actually save the most common computery entity you deal with' is just a strange state of affairs we've somehow Stockholmed ourselves to.