I fully realize that "postmodernism" is vague and ill-defined, with multiple conflicting definitions. What I mean by postmodernism is the intellectual and cultural tradition of pessimism and cynicism towards modernity which emerged in the twentieth century and continues to influence large segments of the humanities to this day. The intellectual movement which critiques or outright rejects all universalist ideas about objective reality, knowledge, science, reason, social progress etc.
So, with a point of departure no earlier than 1900, what could have prevented the rise in prominence of postmodernism?
I imagine a less bloody twentieth century may have helped (no world wars, no holocaust, fewer wars & genocides in general).
And without postmodernism, what would the intellectual landscape look like today?