I have sympathy with this point of view when it comes to journalism, corporate writing, manuals and explanatory books. But novels (can be) more than that. Imagine a poem that followed your rules - yes, you could get the ideas across, but would it be poetry? It might be, but poems don't have to be simple - part of their joy can be their ambiguity, their multi-layered nature that tickles your brain without being direct about it.

Novels can have this aspect too. The English language is a rich, nuanced, complex thing and it feels sad not to be able to take it out for a spin sometimes. That doesn't mean being deliberately obfuscatory (too fancy?) but it does mean allowing the novelist to tell a story in their own way.

I think every reader has their sweet spot. I've certainly attempted to read novels that were too hard for me. I've read some where the prose was uninspiring. There is a happy medium which is readable and yet the language itself delights, stretches you just a little bit - where you come out feeling just a little smarter. The trouble is, everyone's 'happy medium' is a bit different... also that sweet spot can vary with time and mood. It's like music. Sometimes you might want something challenging, at other times something familiar and 'easy'

(the context is his first meeting with Martin Amis, a lifelong friend)

Lovers often invest their first meetings with retrospective significance, as if to try and conjure the elements of the numinous out of the stubborn witness of the everyday.

Now that, I admire, and yet I can't imagine writing it. The only word that's at all unusual is "numinous."

I don’t see why this would be true at all. Language is an extremely recent innovation, with most biological and conscious experiences happening nowhere in the vicinity of it. Also we know there are ideas that can be expressed in one language and not in another, largely due to the need for cultural conditioning (i.e. repeated firsthand sensory experience)

Here’s a trivial example: describe the color blue to someone who has never seen it themselves.