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.
The comic I remember was overwhelmingly about the banalities of working as a corporate engineering type. One of his peers was black, another was a woman, and they were not the butt of the joke. Pointy hair boss was.
AFAIK, the only non-White recurring Dilbert character was Asok the Intern, who was Indian.
A black character (who Adams himself described as the first black character in Dilbert) did appear in 2022, but, well...
https://www.reddit.com/r/onejoke/comments/ugunog/after_33_ye...
Still. "White guy writing about banal stuff must be white privilege/resentment" is a real stretch to apply to the comic during its prime. Your 2022 example only highlights the contrast.
The closest example I could think of from the 90s was a riff on whether you're supposed to open the door for women or not in these modern times, and it felt much more "confused everyman" rather than "aggrieved partisan".
The origin story being resentment over his perception his career was not advancing because of women and minorities isn't an inference from the fact that he is white, it's based on his own description of the reasons for his dissatisfaction with his career before becoming a full-time comic artist (and not descriptions which first emerged in the 2010s or later, though I think the his description of his final exit from Pacific Bell as "being fired for being white" was a later evolution, but his story of his perception that he was passed over for higher management at Crocker National Bank where he was already in management and, and passed over for any management opportunity at Pacific Bell, because of a preference for women and minorities came out much earlier.)