My counter to your comment, and my own personal experience, is that doctors are fully aware of the manufacturers conflict of interest. They know that the drug companies will present everything in the best possible light.
Other things that exist to counter this bias are competitors, who will provide a different perspective and most importantly, the FDA that regulates all pharmaceutical promotion for accuracy and will quite swiftly drop the hammer on a company that bends the rules.[1]
Yeah, but this starts to break down when the pharmaceutical representatives can give laundered incentives(fancy "educational" dinners, "educational" yacht parties, etc.) to prescribe their product. In the US, pharma reps can see the prescription amounts of doctors to verify that they are actually prescribing their product(last I heard from a pharma CRM company in 2016). This seems deeply and fundamentally unethical.
Then you bundle all that up with the various studies that show that doctors(as with all professions) do a poor job with continuing education so that they are further inclined to take the recommendation from the pharma reps(which can be seen in the roots of the opioid crisis), I don't think we're in a very good place from a regulatory standpoint.
Not to take a position in this debate as a whole, but I just want to interject that there is research suggesting that you actually are more likely to be affected if you are aware of the other person's conflict of interest. (Can't find a link right now...)
If memory serves me right, the theory is that it makes you overestimate your ability to stay objective and unaffected, so you're effectively lowering your guard, or something along those lines.
You should read "the honest truth about dishonesty" by dan ariely where scientific studies of conflicts of interest found folks fall for this stuff unconsciously and repeatably.
Other things that exist to counter this bias are competitors, who will provide a different perspective and most importantly, the FDA that regulates all pharmaceutical promotion for accuracy and will quite swiftly drop the hammer on a company that bends the rules.[1]
[1]https://www.fda.gov/drugs/warning-letters-and-notice-violati...