This is a very unhelpful pseudo question, that adds nothing to the conversation but can easily derail it. Do you have at least a source for that "claim"?
But I remember seeing statements here and there that at least half the "cost" of a new drug is marketing. Commercials, paying for 'conferences' for doctors etc.
Not going to search for citations, I'm sure you have something ready to prove me wrong and show how 95% of the cost is blood, sweat and tears.
The marketing is critical because they have a limited window of time within which to recoup most of the development costs. If adoption ramps up too slowly, the company will not make enough money to offset the investment. Marketing improves time to revenue for a product where exclusivity will be short-lived. If they didn't spend on marketing, the R&D wouldn't exist, so it is kind of weird to act like this is a waste of money.
It is like saying solar panels are bad for the climate because manufacturing them requires CO2 production.
It shouldn't need to be said that no one would do marketing if it didn't more than pay for itself and offset the costs of the thing being marketed.
You are literally going to use “build it and they will come” as an argument on this site? The empirical evidence that you are wrong is overwhelming, it takes an enormous amount of effort to connect customers with a product no matter how perfectly suited the product is to meet their needs. Startups spend more time on this question than almost any other.