Publishing is very squeezed, and has been for many years. You can't earn a living writing, these days. (Nobody counts JKR as part of publishing, she's the perfect example of a 'black swan' outlier.)
So we're left with a reduced field of opportunity. There's grant funded writing, which increasingly is required to tick certain boxes and uphold certain ethical standpoints (and not others), academic writing, which has similar pressures, mass market fiction which really does need to be churned out to formula, or hobby books by those who can afford to write them. Self publishing and tiny indie presses have their own issues.
Added to that, there are no mid-market independent presses anymore. They've all been bought up by the 'big five'. So fewer and fewer opportunities for diversity, plurality, books that break the mould or are actually meaningfully different than the rest.
It's always been an industry that follows the 'throw the spaghetti at the wall' model; I think it's badly failing, now. A shame, and we are left far culturally poorer because of it.
Er, sorry. /tangent.