Also, rather than restore the previous state when I swipe to go back, it has to reload the page from scratch
I've encountered cases when both behaviours would've been desired (either use the cached version, or the latest version), so I think that's neither a point in favour nor against.
Well, Safari caches resources, it just doesn't seem to cache the actual runtime state of the page like Chrome does (look for bfcache). The bfcache article claims Safari and Firefox do it too, but I have both in front of me and no they don't (or it's not good enough).
I think real caching is superior because you can manually reload if you actually needed that, but you can't go in the other direction.
I've encountered cases when both behaviours would've been desired (either use the cached version, or the latest version), so I think that's neither a point in favour nor against.