That is turning out to be one of the most misguided xkcd comics ever.
The problem is that bot traffic is virtually definitionally not neutral; it is trying to attempt some goal, overt or covert. That might be advertising, link farming, submarine placement, karma whoring (to some later use), vulnerability probing (if only for anti-bot defences), information gathering, or various forms of propaganda: disinfo/misinfo, instigation, or just overwhelming channels with noise (the Chinese model). Even putatively benign and declared bot rapidly become at best annoyances as experiences on Reddit and Mastodon are showing. Good bot practices require very judicious and closely administered use. Wikipedia and IRC service and janitorial bots are examples of positive use. Each is controlled and deployed by specific administrators.
I've seen and reported appearance of covert bot accounts across multiple networks. They never prove benign.
All of these reduce the human-to-human trust of a network -- the presumption that a given interaction is with an actual human, absent grossly obvious ulterior motives.
As a few others have noted, excessively mediated experiences seem to become lower rather than higher trust, a characteristic I've suspected for some time is a generalised case, with some possibly exceedingly deep cultural and sociological implications.
This rapidly veers off into my own hypothesis and theories, but; looking back at histories of communications technology and practice, particularly over the past 200 years or so, the practice of imprved coms is parallelled by routinised and standardised formats, and far less obsequious and religious language. (See especially research by James Beniger and JoAnne Yates on commercial and business communication). As comms latencies fell (from weeks or months to days or minutes, or less), the need to specifically prove and swear allegiance, loyalty, thankfulness, and debt in every exchange falls.
I also suspect (though I've found no discussion) that a major role of empirical religious traditions, which every major preindustrial empre seems to have had, is building a shared social trust basis. This would be a social mechanism of religion.
Other interesting observations are that it was the greek god Hermes represented trade, merchants, commerce, roads ... and thieves and trickery. It was as the first high-spped comms networks (telegraph) and motorised highway system emerged (Mississippi steam-powered river boats) that the idea of the confidence man emerged in Herman Melville's novel of the same name. The elements of distant communications, and speedy entry and exit, create the space required for fraud.
A different tack is taken by Kyle Harper's The Fate of Rome, looking at the co-emergence of disease, epidemics, and plague with both urban density and high-volume (for the time) trade, commerce, and travel. Though he doesn't touch on fraud.
The whole question of how and why high- and low-trust cultures develop is an interesting one.