That's the thing with activities anyone can do - pretty much anyone does. And 90% of everything is... not great. I think a lot of those doofuses on LinkedIn just portray some level of success when in reality they're desperate for business, at least some folks I spoke to that are very active there were like that. But that's anecdotal evidence. Depressingly, just how some folks succeed with just a good offering, some folks just succeed with good marketing. But I suppose if you manage to be reasonably good at both, you have a good chance to succeed.

> This pov assumes that everyone engaged in "marketing" is remotely competent at what the are doing

What? No, it doesn't assume any such thing. The mere fact that marketing is necessary implies nothing about the skill of those attempting it.