While Mars gets all the attention in sci-fi, Edgar Rice Burroughs (of course) penned a five volume series back in the day (1930s) and has been the epic adventure on the clouded planet ever since.
He uses his classic formula: Earth man lost on another world, meets the girl of his dreams (native of the other world), must face peril after peril, often losing and rescuing his girl in the process. In spite of being a well-used plot in his books — and an archtype for much of pulp fiction that would come later — he creates fresh backdrops of alien cultures and beasts. One can detect allusions to nations or ideologies of our own world in his creations, yet he’s always subtle, never in your face with parallel meanings.
Is there anything wrong with an entertaining story that lets the reader disappear into another world? Must every book be on some sort of crusade? No, but all good books have some depth to them. Others try too hard and come off unintelligent to the thoughtful reader. Yes, there are those who like books that explicitly affirm their worldviews, no matter how poor the presentation.
Burroughs’ books, however, decades after they were written remain fresh, relevant and, above all, entertaining.