It sounds like you're saying that new hackers don't have a good place to go for reliable information, and in the 01980s they did, because magazines and books were reliable, and now they're gone? And that it's harder to get electronic parts now than it was in the 01980s?
I think I disagree with both of these. But I'll only tackle the first one.
With respect to reliability of information, I agree there's an enormous amount of misinformation out there now, especially in places like YouChube. But ⓐ there's also excellent reliable information out there on Wikipedia and Stack Exchange, for which there was no equivalent in the 01980s, and ⓑ even YouChube isn't that bad.
Let's take a look at the particular example you picked, misinformation or lack of information about solder types. My top ten hits for [how to solder] are https://www.youtube.com/watch?v=oqV2xU1fee8 https://www.youtube.com/watch?v=Zu3TYBs65FM https://www.youtube.com/watch?v=6rmErwU5E-k https://www.youtube.com/watch?v=Fp37DPZVdRI https://www.youtube.com/watch?v=EW9Y8rDm4kE https://www.youtube.com/watch?v=Qps9woUGkvI https://www.youtube.com/watch?v=VxMV6wGS3NY https://www.youtube.com/watch?v=IpkkfK937mU https://www.youtube.com/watch?v=qxqZJH3SfN4 https://www.youtube.com/watch?v=ZwU9SqO0udU, which mysteriously all ten are about soldering electronics and none about plumbing. Of these #1, #3, and #5 talk about lead-free solder vs. leaded electronics solder, and #2 does that and also specifically warns you away from silver solder and acid flux. Only #4 (which is of very poor quality), #6, and #7 omit information on the question of different solder types. (#6 does mention "rosin-core solder" but doesn't explain that there are other kinds.)
Item #8 is a special case: it talks a lot about flux, shows rosin-core solder highly magnified, talks about solder composition... but it incorrectly claims the rosin is "a weak acid" and doesn't really mention the existence of other types of solder until a passing mention of lead-free solder near the end.
(I, uh, ran into my writing deadline before checking items #9 and #10. Comments welcome.)
So, even though YouChube is much less reliable than Wikipedia or Stack Exchange, I think that if you were to spend fifteen minutes watching randomly chosen videos that YouChube serves you up when you google [how to solder], you would find out that you need special electronics solder, and most of the other information you got would be correct. And you would have spent fifteen minutes watching experienced technicians explain and demonstrate proper and improper soldering technique under high magnification.
Of course, this is still vastly inferior to being taught soldering by someone who knows how to solder! But we weren't comparing YouChube to apprenticeships, were we? We were comparing YouChube to reading Popular Electronics and, I don't know, the worthless pap that passed for "educational TV" in the 01980s. PBS or something. Most PBS shows were the TV equivalent of WIRED Magazine: just enough information to give you the illusion of understanding, but not enough to actually learn anything.
As for the reliability of magazines and books, I recall my Encyclopedia of Science and Invention in the late 01980s solemnly informed me that computer RAM consisted of magnetic cores and that fluidic integrated circuits were commonplace in missile guidance systems. OMNI Magazine was full of UFO speculation. The how-to booklet that came with my Radio Shack 200-in-1 electronics kit gave me wiring diagrams for how to wire up a Hartley oscillator, but no equations and not even the name "Hartley oscillator", so I really had no hope of ever understanding how the damn thing worked. In high school in 01992 I took a "pre-engineering electronics" class, whose textbook explained to us that TTL logic had propagation delays around 5 ns, while CMOS logic was more like 20 ns — true in 01972, but that was the year the school was buying a 200MHz DEC Alpha αxp server, which I naturally deduced must consist entirely of ECL.† And I recall getting very excited when I started reading books in the school library about the Bermuda Triangle, and then there were the Hare Krishna books explaining how worms bite babies in the womb and how Krsna Consciousness would liberate you from the cycle of rebirth, and the books explaining how to develop your psychic powers...
So I think YouChube and BitTorrent and the like have vastly improved the access-to-information situation, even in the specific example you chose, and moreover there are vastly better information sources around. I already mentioned Wikipedia and Stack Exchange, but there are also reputable open-source projects like QUCS and yosys, there's ##electronics on libera.chat, there's Hackaday, there's still Don Lancaster, there's Kuphaldt's excellent open-content textbook at http://www.ibiblio.org/kuphaldt/electricCircuits/, and there's the Internet Archive; and, for those living in places where they're legal, Library Genesis and sci-hub provide instant access to a depth of knowledge on nearly any topic that vastly exceeds what even any university library had in the 01980s.
There is vastly more misinformation available. But there was always plenty of misinformation. There's also vastly more of precisely the solid, curated material for new people and advanced people that you're looking for, and it's immensely more accessible!
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† The Alpha was of course a CMOS microprocessor, like every microprocessor I've ever seen or heard of. CMOS propagation delays were down below a nanosecond in 01992, but our textbook was outdated by over an order of magnitude.