This isn't a perfect example but Cormac McCarthy has been my favourite author for years now, and his first major work Suttree was from '79.
My all time favourites novel is Blood Meridian from 1985. If you're familiar with metamodernism, which is basically very modern works that have their cake and eat it when it comes to modernist ideals and postmodern critique, you'd clock that practically every western is either a modernist white hat western or a metamodern "the west is grim and hard, but also fucking cool" western. The only straight postmodern takes on the west that I know of are either Blood Meridian or pieces of work that take direct notes from it, such as the films Dead Man from '95 (except maybe the Oregon Trail video game from. 85'). Blood Meridian otherwise is a fantastic novel which meditates on madness and cruelty, religion and fate, race, war and conquest and so many other themes. It also has one of the best antagonists ever written in Judge Holden, a character who I would have called a direct insert of Satan if not for the fact that his deeds and the novel as a whole are closely inspired by true events. I feel the novel takes inspiration from Apocalypse Now, specifically the '79 film and not Conrad's 1899 novel Heart of Darkness. If you enjoy that film, you're likely to enjoy this book. The opening and closing chapters are fantastic, but I often find myself re-reading chapter 14. It has some of the best prose and monologues of the entire novel, and encompasses in my opinion the main turning point of the novel.
His other legendary work is The Road, a 2006 post-apocalyptic novel. I'll talk on this one less but as our climate crisis grows and our cultural zeitgeist swings more towards this being the critical issue of our time, the novel fantastically paints itself as both a fantastic warning to our 21st century apocalypse and the unresolved 20th century shadow of nuclear winter. Despite this, it hones in on a meditation of parenthood and could be considered solely about that, with other themes of death, trauma, survival and mortality being explored through parenthood. Of course the unsalvageable deatg of the world that make the setting also makes this theme extra tragic. There is an adaptation into a film from 2008 but it isn't anywhere near as potent as the novel and I'd suggest should only be seen in tandem with reading the novel. The prize of this novel has really evolved to fit the novel too. McCarthy is renowned for his punctuation lacking prose, but where Blood Meridian is practically biblical in its dramatic and beautiful prose which juxtaposes the plain and brutal violence, The Road sacrifices no beauty in it's language but is so somber and meanders from mostly terse to so florid, while also always perfectly feels like how the protagonists are seeing their world.
I definitely doubt the average comic author is pro billionaire. I think having an absurdly rich protagonist is just interesting for plot, not just does it easily justify the funding, but it easily generates a lot of plot hooks.
Growing up, I absolutely loved Peter Parker as just being the average broke kid, but I was never excited by the plot that generated that was largely school drama or conversations in small apartments.
On the other hand, there are plenty of cool things that Bruce Wayne gets to do. Sometimes he blends in with high society functions and you get an almost James Bond style investigation and sometimes you capture that Dracula style recluse skulking in his enormous manor, and both of those are very evocative even before you consider how it funds his heroics.