There is some science fiction that goes beyond more adolescent themes and character development. A Canticle for Leibowitz is one, Dan Simmons’ Hyperion is another. Hyperion uses a storytelling format similar to Canterbury Tales but told better, and with a much better plot.
I would definitely include Dan Simmons’ Hyperion.
But I also think almost anything by L. Neil Smith is good. His science fiction world is essentially a libertarian view of the Universe.
https://lneilsmith.org/lns_books.html
I knew had had been in bad health, but until looking for his book list just now, I had not realized he passed away a year ago.
I agree with you on Hyperion. When I recommend it to others I always tell them if they start reading it and like it immediately go out and buy Fall of Hyperion those 2 books are really 1 book and they will be ticked of waiting to get second volume. Endymion and Rise of Endymion are also really 1 book. They can be read later