Do you use any products from a one-person shop? They will be so much more likely to ask you real questions. Not guaranteed, of course, as some people are just clueless. Those usually don't last long as business owners though.
Is it possible that all real product ideas come from the mind of a single person, understanding and interacting with other people as actual people? And corporations are some sort of Thing that takes humanity and squishes it into a Box, a Box with one very narrow goal: to freeze the product idea from the single person and mass-produce it, "scale it up" so that millions of people are aware of its existence and are able to use it?
I mean, Google didn't even invent Google Docs. Some random little startup did. Google just bought it, then made it discoverable and usable to millions.
Which is not a small thing, I guess. But I don't know what the marketing department is for. Other than putting Google Docs on billboards, maybe, or their digital equivalent.
As for the marketing department - depends on definition, but assuming you mean (as it mostly is nowdays) comms, it's two things:
1. Making sure that potential future customers know you exist, so when they enter the market to buy, they know you're relevant and can purchase from you.
2. Making sure that when someone is in the market to buy now, that they're more likely to buy from you, because you have a compelling reason for people to pick you, and not the other brands in the space that they can think of.
Mostly 1, some of 2, if the marketing team is good. Ratios vary as to how much though by more than you'd think, depending on industry, customer lifecycle, brand maturity and so on.
At least in most of the modern world. I think this effect is a _little_ weaker in China. It definitely used to be much weaker in the West too, at some point in time. But individualism, cultural capture by big capital, yaddah yaddah.
But honestly, I think the biggest issue is that leaders don't even realize they have this problem. I don't think it's the lower level employee being lazy. I think it's the leader not realizing how important customer and market empathy is, and not baking it into the company culture and processes. I agree wholeheartedly with the op comment at the top of this thread.
It's one of the reasons why monopolies lead to such bad experiences and products because there's no competitive pressure to empathize with the customer.