I think today's self-proclaimed informed authority compares pretty well to yesterday's hobbyists, at least. Access to information today is just so much better than it used to be. I've got a passing interest in ancient history, and I own a number of books, but I'm hardly an expert. This morning I watched a YouTube video about the origins of cavalry and how long it took after the domestication of horses before anyone tried riding into battle on the backs of the horses. Chariots, on the other hand, were widely used much earlier. Just from that 20 minute video I learned a lot about an important part of history, and I know that if I wanted to I could spend a few hours, right from home, learning far more about it than I could have gotten from days or weeks of research in libraries when I was growing up.
How many times have we had that conversation with someone who knows their topic backwards and forwards and after minutes, we have a deeper understanding of it than almost anyone around. Expand that out to an hour with a few key/relevant questions to frame the conversation and it is totally believable.
That said, bibliographic databases have been around since computers. They were just restricted to librarians, mostly because of infrastructure issues.
The same goes for the anti-vaccination folks, the "climate change is not real" folks, the anti-fluoridation folks, the anti-bike lane/trail and anti-public park people [1], and more.
[1] Yes, they are real. Bike lanes and public parks, they believe, are part of a UN agenda to make cities more attractive so that the population will concentrate in the cities, which will make it easier to impose martial law and confiscate guns. Before the internet this would have been a total joke. Now those people can organize, and show up in large groups at city council meetings considering parks and bike lanes, and get those projects killed.
Though it was easier to just control the masses with TVs and radios - they cant talk back, so you can spout whatever you want at them and they'll follow.
Pretty sure that Trump would've been just as popular today if the Internet was not around.
The internet has made people wiser and more savvy too. They've stopped one interest group from being able to make their views and messages seem like the only one.
I thought it was a useful source for Call of Cthulhu campaign set in 1920s, where investigators are supposed how to use libraries effectively.
Link to review of English translation: https://mitpress.mit.edu/books/how-write-thesis
And oh, I recently tried starting a habit of keeping an up-to-date directory of greppable markdown notes with links to the papers and books I've read, directly inspired by Eco's index card system and his gigantic private library.
I am one of the pre-internet oldies and recall how you had to go to the library, and find the book on the topic you wanted to research. It was a case of hoping it was there and not loaned out already, or too old an edition. Quite often, it would already be loaned out, and you had to wait a week or two and then go back, hoping it had been returned on time.
Experts back then, were really experts. There was a clear line between expert, hobbyist, and passing interest.
Now everyone see's themselves as an informed authority, after a few minutes googling and reading a wikipedia page.