Why are some great novels difficult to understand? (post 2): Others would say they are pretentious or written in the style of peculiar literary movements.

Pretentiousness

https://www.theatlantic.com/magazine/archive/2001/07/a-readers-manifesto/302270/

https://en.wikipedia.org/wiki/A_Reader%27s_Manifesto

Literary Movements
https://en.wikipedia.org/wiki/List_of_literary_movements