There will be those that don’t change their practice ever once they graduate (seen a few).
Things get more complex when you have dozens of treatments for a condition with no clear winner.
Before I got in the industry I thought “what the hell does marketing do?”. Then once I saw what they do, I realized, no, most drugs don’t sell themselves, there is too much inertia for doing the same old thing.
If you develop yet another blood pressure drug or cholesterol drug and want GPs to prescribe it, you're going to have an uphill battle.
A blockbuster drug for HepC (where treatments before weren't particularly effective and had ugly side effects) will have a much easier time becoming well known amongst the specialists that treat the disease.
The government isn’t going to get away with hiring entire teams based on looks and then have a marketing line item for free fancy lunches for people that are definitely not starving.
Choosing Wisely is a broad approach that is somewhat like you described.
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...
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.
[1]http://phrma-docs.phrma.org/sites/default/files/pdf/phrma_ma...
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.
The job of the marketing department isn't "best drug for patient". That's the doctor's duty. The marketing department is there to bring awareness of the product to both doctor and patient. There is no conflict of interest at all.
And there is plenty of research demonstrating that this is exactly what they do, and that doctors are indeed swayed by it, because, as you say, they don't have the time to do keep up with it all on their own.
And yes, there is a fundamental difference to consider here: My doctor has a fiduciary responsibility to do what's best for my health, to the best of their ability, and drug marketing compromises that. By contrast, nobody has any fiduciary responsibilities related to which brand of toilet paper I use.