Often, yes, especially on relatively simple pages that relate to geography, mildly famous people, etc. But take a look at Wikipedia's page on Facebook, which is now a 539-source accretion of diverse headlines as they happened, now held together only by subject headers that are the digital equivalent of very large paperclips. Or a ship's log.
Fixing this would be brutally tough! We're talking about what's now a "semi-protected article," alterable only by trusted players, because otherwise it's more likely to be defaced than improved.
In fact, looking at the Talk section for the Facebook article, it looks as if it was deemed a "good article" from 2006-2011 but then lost this status.
A telling comment at the time: "Compared with the latest reviewed version of the article, the prose is very choppy and unclear. In some sections, every sentence seems to function as its own paragraph, while in other sections there are random paragraph separations where there shouldn't be. The entire Website section is a mass conglomeration of Facebook features that needs to be sorted out in some way."
What's visible now is beyond the stage where incremental fixes (or additions) can fix things. Meaningful improvement will come only from a top-to-bottom rewrite and rethinking of the article, so that Facebook's role, history and features are presented with the clarity and insight of author(s) who can put all the pieces together in a framework that's strong enough to overcome the "ship's log" problem.