A blog was the selected method of online personal self-aggrandizement throughout most of the 2000s and has been largely superseded by social media by the 2010s.
Blogs were very multifaceted in the sense that it successfully served as a dynamic method of uploading information, beyond the constraints of old static websites; in this way, blogs were the cornerstone of the Web 2.0. The type of information uploaded, however, needed to have this same chronological dynamism in order to optimize the purpose of the blog's framework as essentially all of them share the characteristic of displaying posts in (reverse) chronological order - the concept of a journal comes to mind very naturally, almost like an extension: journals are chronological, personal, and meant to express a person's thoughts, events and beliefs in the written form; blogs, in this way, served as digital journals, not only with the capability of streamlining the writing process but also the possibility of opening them to public consumption. Eventually the public, through comment sections, even managed to talk back, subsequently making the audience more tangible in nature.
For this strictly personal type of blogs, which were the majority, the attractiveness behind throwing your thoughts out to the public shifted to a more narcissistic type of web usage, i.e. social networks. A “blog feature” became commonplace in many websites that had other uses in mind, but still fostered a sense of both community and individuality, such as Deviantart. Websites dedicated to hosting blogs went as far as making a tacit blogging community through not doing much more keeping them all in the same place, like what Livejournal did; whereas more orthodox blog platforms had to resort to “linkbacks” (citations, mainly) or “blogrolls” (affiliations, an emasculated successor of the old webrings) to give a sense of community (the “blogosphere”), sites like Tumblr merely streamlined the process by making this linking1) of blogs part of the site framework itself. Blogs stopped being individual entities (at least they were as such prima facie) and became the amalgamated result of community blog interaction - this, as well, reflected in its content and made it even more palatable to users. Sites with “blog features” and strong linking of its users took on, and the examples are so commonplace they barely need to be named at all for them to be conjured in your head. Something that people keep forgetting purely because of repeated exposure, enough to merit the remark, is that Twitter is and has been a “microblogging platform”, and it works exactly like blogs do, or used to do. Twitter killed the Blogspot star.
So what about the “classic”, “oldschool”, “orthodox” blogs, like Blogspot or Wordpress? As a repository of downloads and static information they can become hard to navigate as they're sorted by date (tags are optional, often neglected or misused, and their navigation usually a hassle due to both lack of proper categorization and the clunkiness of outdated interfaces), and websites that simply offered more snatched away a good chunk of its userbase. Not a lot of point in updating that which has been reinvented, mostly successfully - and turning back the clock to a more static community is impossible for a userbase that tasted the fruit of contemporary online communities and connections between people, both real and their pseudonymic entities2).
One of the final blows to these type of blogs were by far the end of Google Reader, the largest in the gamut of RSS aggregator software. By then, blogs were already somewhat in life support: the problem of linkbacks and blogrolls is that they were ultimately endogamic in nature and the circle closed a bit more and more every day, either because of abandonment or migration. One of the few good ways of getting people engaged in reading and keeping up to date with blogs, plus remembering the existence those blogs vaguely visited or vaguely updated (not so much for discovering new blogs, however) was through RSS aggregation. It's difficult to herd the dispossessed users of a defunct piece of software to an alternative, moreso when the alternative is not as good or not as readily available3) and then the things you used to read and even its authors can now be found elsewhere, where suscription is integrated in their new homes and doesn't need an external toolset.
More traditional blogs survive in news websites, but only very few of them offer personal blogs with personal words; content is the result of the conglomerated behemoth that constitutes the site, a mass of multiple writers that, ultimately, only give birth to sterile text. Personal transcendence through blog writing (or writing, or static pages in general) has been either discarded or kept on hold by both past and present user generations. Thus, the slow death of traditional blogging marches on.
I don't pretend to evangelize you on this, honestly. But the one good thing I like to point out about personal wikis is the virtues of traditional blogging with the addition of atemporality. Unlike blogs, a sense of chronological continuity is optional rather than mandatory, so it offers a better, more accessible way to display static content.