Art is different. If we bowdlerise it , it loses a lot of its point.
No one is talking about censorship or bowdlerisation. People make choices every single day what art they choose to consume, and every single commercial art form spends huge amounts of money in things like publicity and market research to decide on cover art and book jacket blurbs, with the sole intention of reaching the audience demographic who are most likely to choose that particular item.
Giving someone a tiny bit of extra info about content doesn't affect, change or impact the actual book or piece of art in any way. It simply doesn't.
The suggestion that films are mere "entertainment" and thus unimportant while books are "art" and sacred to being cheapened by content warnings is just bizarre. How does a Barbara Cartland or Dan Brown novel stack up against an arthouse film or a documentary film about Rwanda?
Giving major trauma survivors a choice of what art to consume is not remotely bowdlerising things.
but if I hadn’t read. It, how could I have hoped to understand what Hardy was about?
There are far more books in the world than any of us can possible read. Nobody needs to read any one specific book. I read at least 100 books a year, but I'm sure there are plenty of books you've read that I have not read, and vice versa. Because people have different tastes.
I read King Lear, Macbeth, An Evil Cradling, and tons of non-fiction books covering everything from the Wars of the Roses to the Belgian Congo atrocities while a student during the same time period I didn't want to read the incest book.
Why should I be forced to read a book about a father raping his daughters, when there are so many other wonderful and important books in the world?