Difficult social issues -- or simply scary, exciting ones -- can be safely explored in fiction. I'm too lazy to research the links, but there are established arguments that romance novels are a space for women to "try on" new social norms around gender roles, sex, social mobility, etc. We walk a mile in a fictional character's shoes, and our world opens up.
I've written steampunk in the past as a way to critique society now by re-imagining history. Post-traumatic stress and the abandonment of returned soldiers is a theme in The Icarus Plot.
Self-publishing really opens up the potential for social commentary in novels because its time frame is so fast. Where an author with a traditional publisher may wait 2 years to get their book published (up to a year just to get a publishing contract, and then, fitting it into the publisher's release schedule), a self-publisher can get a book out in a month, once written (if they're incredibly organised and have their editorial team and cover designer scheduled).
This means authors can now truly write to current issues.
What will this mean for the genre of books written in the future? I don't know. But I do think novels/novellas have a new potential niche. They will become advertising! Social commentary poses questions that encourages us to see our world differently and to act differently within it. This is what advertising also seeks to achieve.
Advertising/marketing gallops into any opportunity that opens up. I really wouldn't be surprised to see political campaigns hiring novelists to write a series in support of an issue their candidate is campaigning on. A big travel agency could easily partner with authors to push a region or adventure tourism activities.
Fiction is a product that can push other products. It's worth being aware of this potential, even if it appals you!