It took me about ten years to figure out that Twitter is a cesspool of useless noise and ego. Everybody tries to outdo each other with noise and follower count. What Reddit does right is focus on topics, primarily, not personalities. (Although I actually like the new user profiles, since they tend to be secondary focus).
Twitter could have been something different, and I think that expectation for something more got priced into what it is valued at today. Based on Twitter's current market cap (12.12 billion dollars!) it's already overvalued by a LOT; and there's really nowhere else for it to go but down. Any new users it gets are just bots or other political warfare tools.
For me, the final straw was that Twitter wouldn't "verify" Ecosteader as a legit account. So I deleted my Twitter accounts, sold a small investment I'd opened a couple years ago, and now spend more of my idle time reading Reddit rather than Twitter. And I feel so much better for it...
A subreddit is far more useful than a hashtag... it has stay power, searchability, and (like Twitter) is the kind of place where people will vent and where companies can interact with customers / users. The key for Reddit, I think, will be to do what is right for its users to achieve information awareness... Conde Nast is a news platform, after all. Let's just hope they don't let themselves go the way of Yelp.