If you define quality as "layered and meaty" there are many much better books.

Roadside picnic (and its less Russian counterpart, Annihilation), left hand of darkness, Solaris are all excellent.

If you want culturally influential, surely Starship Troopers, Stranger in a Strange land, anything by HG Wells, 1984/Brave New World, Frankenstein (duh)

The characterization in Hail Mary is just so damn weak, even space opera stuff like Bujold