It is obvious to me when ABC constantly promotes content owned by its parent company, Disney. But I often have to say to my spouse, "You know that's an ad, right?" and hear the response, "Whaaaaaat? No way, really? Now that you mention it..."
There is still a cohort of journalists hanging on to their last shred of professional ethics that will always disclose both paid consideration and corporate relationships between the subject of a story and their employer, but they seem to be slowly dying out.
YouTubers are the least of our problems. Native advertising is already firmly entrenched in mass media.