Many articles lack sources. I just happened to look at a biography of a Swedish journalist, born in 1968. He received some fine awards, and there is no doubt he is notable enough. But the article has no sources. Ten years ago, in 1999, for a journalist born in 1958, I would just look him up in the Swedish "Who's who", which was published every two years. But that title seems to be discontinued. Or if another issue is ever published, it comes with much longer intervals.
Such reference works go the same way as printed encyclopedias and dictionaries. For a young, ambitious journalist today, being in Facebook and Linkedin (and Wikipedia) counts just as much as being in Who's who did ten years ago.
Should I use the journalist's Linkedin profile as a source? I don't think that is acceptable. All sorts of lies could hide there. And users could remove themselves from Linkedin or edit their profile at any time. Old issues of Who's who don't change, they are a stable reference.
But the fact is, Who's who is/was also based on user-submitted autobiographies. The editors made a list of people who "should" be in there, and sent invitations with a form where the person could fill in details about family, education, career, publications, awards, and hobbies. I'm not sure how the editors fact checked the entries. Perhaps the risk of public shame was enough to keep people from lying.
Printed editions have another advantage for the historian. If a Swedish person "forgot" to mention in the 1945 edition that they received a German medal of honor in 1938, perhaps that information can be found in the 1939 edition. In this era of Linkedin and Facebook profiles, how can we ever dig up information from the past, that a person wants to hide?