The decline of blogging, and what replaces it?
You, by definition, read blog posts. But the era of lots of individual personal web sites seems to be on the wane. It used to be everybody had a "home page" and many had one that updated frequently (a blog) but I, and many other bloggers, have noticed a change of late. It can be seen in the "referer" summaries you get from your web server that show who is making popular links to your site.
The change is that they aren't doing that so much. Now, the vast majority of outside readers to this site come from places like Facebook, Twitter, Reddit and Google searches. One might explain this as a fault of my own, but others are reporting the same thing. Dedicated readers through RSS or sites like bloglines are still there but RSS subscription is on the decline too.
RSS subscription (a rather kludgey replacement for the mailing list) is not hard to understand. To RSS subscribe to somebody is to look at everything they produce. In our world of information overload, there are really only so many feeds you have time to look at all of. This blog does 4-5 longish articles per week when I'm not on the road, others can be 20 short items a day, but no matter how much you might like it, there's a limit.
The replacement for "serial" publishing (like RSS, mailing list and newsgroups) has become "sampled" reading. Twitter and Facebook are examples of that. You dip your toe in a stream, either reading what's happening now, or an attempt to figure out what the most relevant things are that have flowed by recently. There are endless arguments (particularly on Facebook) over how that should work but without question the normal user misses most of the updates from their friends if they have a typical set of friends or people they follow.
That doesn't sit well with longer pieces. There is the TL;DR mentality which seems to have given us all shorter attention spans, and the harsh reality that reading even a 4 minute article is out of place in a stream of single paragraph or single sentence tweets or updates. It is frustrating to see a single sentence (often a question) generate apparently much greater engagement (comments, likes, etc.) than a much deeper essay.
Many bloggers have also moved off their own sites to places like Medium, though it's never been quite clear why. (Medium offers better Google pagerank than your own site might have, but I presume for most writers does not point many readers to you if you don't reach their front pages.)
The value of the serial
As I come up to 40 years of internet life (joining my first Arpanet mailing list in 1979 though participating in BBSs and other email interaction since 76) I am perplexed at how online media have failed to embrace the serial well. In fact, I am not sure it has been done better than USENET, itself almost 40 years old. The thing that's been missing has been the essential component of serial media -- understand what you have seen and what is new. As we've moved to information volumes that nobody can handle, we don't seem to have married the serial and the sampled very well. Facebook has some sense of what you've seen, but it's mostly a frustrating one when you are trying to find things. It keeps showing you the same thing repeatedly if it's getting active commenting, rather than just highlighting the new comments.
News has also missed out on this. When I built ClariNet, which used USENET tech to provide a very high-volume serial news experience, my goal was also to rank all the stories so you could come to it and say, "I've been away from the news for 4 days, show me what I've missed, ordered by how important it is."
Another thing that's been missing is an understanding of the value of the infrequent but valuable posting over the frequent and brief one. To realize that if a columnist writes only once a week but makes it good, you want to see all or most of those, but if a tweeter puts out 50 tweets a day, you will want to define what fraction of them to see.
The rule of Facebook
Everybody has also noticed that people greatly prefer to comment on stories in the place they read them, in particular on Facebook, instead of on the story itself. In one way this is strange -- a comment left on an original posting should be seen by all who come to it from different locations. But a comment on Facebook lets you discuss with a selected subset of people (friends of your friend) rather than the general audience, and people prefer that. It is also easier, since blogs tend to need anti-spam burdens on their comments.
As such more and more people move their writing and commentary to Facebook, increasing its monopoly. Another trend I am not fond of.
So what's the next step for online writing? Does it centralize completely or will something decentralize it again? Decentralization of media is no longer seen as a universal good in the era of propaganda and hoax news, but it still has many virtues. What do you hope for?