First, the entire sentence is so poorly written as to be almost indecipherable even to a native English speaker, so please do not worry if you don't understand it.
For background, the Frankfurt School was a
"group of researchers associated with the Institute for Social Research in Frankfurt am Main, Germany, who applied Marxism to a radical interdisciplinary social theory....
The members of the Frankfurt School tried to develop a theory of society that was based on Marxism and Hegelian philosophy but which also utilized the insights of psychoanalysis, sociology, existential philosophy, and other disciplines. They used basic Marxist concepts to analyze the social relations within capitalist economic systems. This approach, which became known as “critical theory,” yielded influential critiques of large corporations and monopolies, the role of technology, the industrialization of culture, and the decline of the individual within capitalist society." [The Editors of Encyclopaedia Britannica]
What the sentence you quoted is claiming is that somehow these philosophers "foresaw" the Internet and that our online involvement would ruin our society (it would become "positively dystopian").