@steevc everything you wrote is fundamentally correct. And @enforcer48 gave an accurate and comprehensive answer on how to get away from this.
It seems to me that this is a historical heritage from the time of Steemit. During the formation of the platform, every user from every corner only heard "create unique content and you will be rewarded". Truly unique content often implies deep and specific topics. Which are not interesting to the mass user.
As a result, we got a fairly authentic social platform, with a certain type of content, for a limited number of users. Although, oddly enough, posts about food and cooking feel very good here. Obviously any social groups love food :)
It is possible to avoid a content conflict only by dividing the reward pool- through communities.
I don't think unique content has to be long, but some types do need longer posts, e.g. food, travel and in-depth articles. Hive could span everything from Twitter to Medium in my opinion.