There's also a lot of tinkering and breaking things that is necessary to develop a deeper understanding of a piece of technology, without which the manual is far less useful. Knowing where to look in the official documentation is half or more of the battle. Modern attention spans, planning expectations, systems complexity, etc. are not geared towards developing this deep understanding.
Moreover, the number one tool developers who cut their teeth over the past ~20 years have relied on to help them find the right answers, Google Search, has degraded massively in quality lately. Stack Overflow arguably breathed new life into search engines for a while, until SEO-hacked junk overtook it. Who can forget the classic forum posts "I fixed the problem [no details]" or "Why don't you Google it [even though this is the only meaningful Google result]". Even Stack Overflow runs into those issues, sometimes, though.