@rabbit_fighter@bookstodon hmmm. My recollection of 2001 is that it's not super mature in content. Dystopian stuff might work if that's not a form of too mature. Starship Troopers, (NOT the movie which is too mature for me), 1984 and Animal Farm, perhaps.
The Broken Earth trilogy (hat tricked the highest honor in Scifi with three straight Hugo awards) is great and I don't recall much sex (it is alluded to).