Ignorance isn’t quite the same as “stupidity.” We can give access the information but we don’t control if people use it, and how intelligently they use it. Give the average person all the data NASA has and see if they can successfully build and launch a manned mission to the moon. Most cannot. We have to build a foundation of knowledge to understand more advanced concepts. At some point every human will reach a point where they can’t understand anything more- for some that might be Quantum Physics and for others that might be “other people aren’t so different than you and deserve an even shot at a life like you’d want.” Gilbert Grape isn’t launching rockets any time soon- and more people fall closer to the Gilbert Grape end of the spectrum than the Einstein end- ironically however people below a certain intelligence lack the intelligence required to recognize their lack of intelligence.
Problematically- we once relied on experts of intelligence to put things in a way we could understand without 20+ years of subject matter education and experience, and to tell people who lacked that background or the intelligence to reach that understanding what to do. Of course around the globe for at least 60+ years we’ve had a light shined on the fact these trusted advisors were often lying or manipulating information for their own agendas. People rightfully don’t want to put blind faith in an unknown expert supposedly working in their best interests behind a veil their own ignorance or intelligence level can’t penetrate.
So with a combined sum of human knowledge, and many agendas and perspectives, and that oh so dangerous fact that the “average” person lacks the intelligence to realize just how unintelligent they are... throw in a splash of human ego which makes most people want to see themselves as “smart” or at least borderline capable of understanding the world they live in- and then give them access to an uncontrolled portal for human thought that reinforces whatever they choose to believe... well... now they have the authority of millions of other less than capables shrieking in agreement.
There is a reason kindergarteners don’t teach kindergarten. If they had the knowledge to do so they wouldn’t be in kindergarten on the level of their peers would they? Likewise- when “joe 6 pack” or whoever gets a think tank started with their buddies- and now those same folks can receive validation from billions of equally intelligent souls... well... “willful ignorance” is the term for a person who refuses to grow because it is inconvenient or otherwise unpleasant to face unfamiliar facts. Human nature changes slower than technology. We all tend to be ignorant by choice.
TLDR: Individuals have limits to what they can understand and the internet lets us reinforce the knowledge we like.