> Pauling is seen as a quack when it comes to vitamin C
Pauling has been portrayed as a nobel-laureate-gone-quack / example of "Nobel disease" in pop science media many times. Often by gullible people who are not actually scientists but more science(tm) promoters like podcasters. They don't usually limit it to the Vitamin C advocacy, but seem to like telling a story of a highly intelligent person "gone quack".
> "Mega-dose vitamin C in treatment of the common cold: a randomised controlled trial"
I don't have access to this but will check later.
> Anderson TW et al, in "Vitamin C and the common cold: a double-blind trial",
I've seen this before and quickly checked again (don't remember everything). They describe and show in Tables II and III a 30% marked-as-significant reduction in confinement to house, so apparently the severity of relevant cold symptoms is indeed strongly decreased. They say themselves that Pauling based his claims on studies showing 45% and 60% respectively (which you have not linked to for some reason). Even 30% is still well over the significance-and-usefulness threshold in my eyes at least, particularly if it comes from a study quite open about intending to "debunk" the perceived quackery. I would figure that the real number is somewhere in-between the advocates and these "debunkers". (Btw, in the discussion they made a weird 70s-boomer claim that consuming four ounces of vegetable and fruit juice per day is sufficient to prevent Vitamin C deficiency, and that 30mg Vitamin C per day is the basic requirement. Also, that they could not (or did not try to) really eradicate the confound of other health measures like other supplements taken is one of the typical problems with nutritional studies.)
About the cancer claims (which I agree should be treated with utmost suspicion, just like any cancer treatment): While I don't have strong stakes in the game to either support or "debunk" it, less than 75 days does seem to be on the short side for a serious disease for me. I wonder how this compares to other cancer medication studies with more profit in the game.
> It's also well-known that the supplement industry makes billions of dollars, among other things, from actual homeopathy, and this money gives them lots of time to write those articles that benefit them.
The supplements industry spends much more of that time and money on fake reviews on Amazon and other social media marketing. Seems to be much more effective for their consumer base than a long-form wikipedia article. Since the profits of the pharmaceutical industry for newly developed patented products are much higher, I guess they have some more money on their hands to hire a few "scientists" to write convincing-sounding long-form articles for pay.
> It's quite well known that people in the pharmaceutical industry, and their friends and family, also get colds, cancer, and more. Do you really think they are hiding a cure from their co-workers, friends, and family?
People in the pharmaceutical industry's marketing departments are hired and paid for writing supportive articles. I bet they are also made believe that they are doing the right thing(tm).
I first noticed suspiciously professionally written "debunk" Wikipedia articles during the Séralini affair - whatever you want to think about it; the time frame in which highly polished professional articles popped up was remarkable. Even otherwise pro-industry centrist-conservative media here got suspicious and wrote about potentially industry-written wikipedia articles. If you need any further convincing who writes WP when money is in the game, check out the article about the "well-recognized musician" Justin Bieber.
I'm not sure why this overall topic triggers so much. A bit more on topic again: Science had very obvious issues with information overload for long time and unfortunately this allows bad players and COIs to exploit the system (recommended reading, also for OPs link: "Science Fictions" by Stuart Ritchie). These developments are out in the open for everyone who is willing to see them. Particularly in recent years. This needs fixing, seriously; and I hope you see it and agree with this, and think along for solutions (as the solution will most likely be technological).
(The "homeopathic dosage" wasn't meant literally.)