Most of the rest seems to have been dominated by English satirical writing or American novelists obsessed with the trifling burdens of suburban domesticity and/or failing libidos, or more recently either meaningless wordplay or ever more navel gazing identity politics.

How much of it could hope to meet any of Adler’s criteria, let alone all 3? By comparison, if I were to stretch it I might suggest works of SF that might address at least his third and occasionally his first criterion. Foundation and some other of Asimov’s works, not always well written but definitely addressing perennial issues. Ditto Dune. Some Bradbury and Clarke. Cordwainer Smith, even when otherwise mere potboiler stuff.

I should stress that I am perhaps being harsh in my first sentence- there is probably more British and other literature than American that would meet Adler’s criteria, perhaps including some of the best work in English by Indians and others. But even most of that is probably not timeless.

And would be amazed if much of anything written after 1945 would reward infinite study. That might apply to other art forms as well as the written.