Historian Niall Ferguson sets up the long context, comparing the internet age to the rise of the printing press, in The Square and the Tower. An accessible short discussion is this podcast episode of Making Sense.
Cory Doctorow has a lot of interesting takes on internet developments & the future, like this Mindscape episode on Technology Monopoly & The Future Of The Internet, and he's written on How To Destroy Surveillance Capitalism.
Baudrillard and McLuhan are key foundational thinkers on the philisophy of media.
But you seem to be asking for something more like anthropology, or sociology. Durkheim's framing of religion is useful, the idea the social cohesion is substantially founded on a community holding 'sacred values' together, or putting things beyond question; and the binding comes from celebration, enactment, and reinforcement of such values. Which can be habeus corpus or free speech, as much as an altar. Jonathan Haidt has interesting ideas in his Liberals and conservatives rely on different sets of moral foundations, about the difference in culture between left and right, and it's origins (mainly herder vs agricultural, and tolerance of ambiguity being suppressed by threat perception during developmental years).
I think Kuhn's approach to knowledge could sustain parallel structures of truth, but his approach has serious problems.
I'd approach the subject as different cultures, bound by different values, and look to the impact of the printing press for parallels (witch panics, conspiracy theories, amplification of religious differences, and eventually, more secular governance & wider spread education).