He was the first to publish an open way to communicate with him in order to out the corporate crazies, and readers did in droves, explaining the inanity of their workplace and getting secret retribution for stuff they clearly couldn't complain about publicly.
A good percentage of youtubers and substackers today actively cultivate their readership as a source of new material. They're more of a refining prism or filter for an otherwise unstated concerns than a source of wisdom.
Doing this seems to require identifying with your readers and their concerns. That could be disturbing to the author if the tide turns, or to the readers if they find out their role model was gaming them or otherwise unreal, but I imagine it is pretty heady stuff.
I hope he (and anyone facing cancer) has people with whom he can share honestly, and has access to the best health care available.
I've come to believe that infohazards are real.
Consider alcoholism: some people never drink anyway, plenty of people can have one drink or a few drinks and then stop. But some people can't stop and destroy their lives. Consider gambling: similar distribution applies. Many people never gamble, many people have a little scratchcard or sport bet now and then, and some people get out of control and sink all the money they have into it.
Gambling is an idea that's a trap. Some people get like this with ideas on the internet. In fact there's an XKCD about it: "can't sleep, someone's wrong on the internet".
Usually there's a single atrocity or injustice that triggers it. Maybe it's real, maybe it's been subject to distorted reporting. But it becomes a monomania. You can't counter them with statistics or variations on "most people aren't like that".