I see it as the antithesis of Islam. Islam is rigid to the max. Postmodernism is anything goes - it’s about denying reality logic, cause and effect, truth, deconstructing (destroying) everything, relativism. It’s the ultimate nihilism.
That, in itself, is orthodoxy and, thereby, the similarity to Islam. At its core, post-modernism enlists the all-powerful state, just as Islam IS the state. Read Antonio Gramschi.
Social justice warriors go around censoring people’s word choice, clothing styles, hair styles, dictating approved beliefs and engaging in mob shaming campaigns to violence to enforce the dogma they imbue with religious fervor.