The number of tags will proliferate so much that no one will be able to really home in on which tags they want to click. It will effectively still be a firehose. I don't think you can solve the relevance problem with tags filtering.
I do because it works under the same concept as IRC channels. While not completely unbounded or analog, the variety of IRC channel combinations you can create is extremely high, yet people congregate/conform/cooperate as to funnel into certain ones.
It may provide some improvement, but...
That doesn't entirely fix rankings within a tag (whales will still drive the top rankings in the tags they vote in) nor entirely rewards for content (since even though I may see more of the content I am interested in, my minnow vote still won't be worth much).
Meritorious rewards are necessary to drive serious blogger effort and vestment in the site (since paid content is their main claim of differentiation from Medium, Reddit, and other similar sites, and the blockchain isn't decentralized any way so the idealism sales pitch isn't defensible). That still doesn't provide a medium-term investment demand to sustain the price and market cap (especially when competition arrives that does provide such).
If Bitcointalk.org is any indication, users are head-headed and will create numerous duplicate tags (as threads they do here). Do I ignore those other threads just because there are more popular threads? Not entirely. Thus there is an incentive to proliferate tags.
I suppose the author can attach numerous tags to his post, but that becomes a pita for the author to keep track of all the various ones, and new tags may need to be added to his post over time to keep his post in all relevant tags.
It would be much better if I could (either automatically or by some manual action) subscribe to like-minded interests and have all those posts come to me, regardless of how the author has tagged them. However, I might share some interests with another person but not all their interests, so merely following another person's sharings will spam me with content I am not interested in.
Another reason to proliferate tags is that others are dumping shit into a tag that I think isn't applicable to that tag. Or some author wants to differentiate her content from other content in a tag. Diversity and degrees-of-freedom will dictate that master tags won't dominate.
I have a design idea of how to get the best of both.