Too much fundamental knowledge is available but we can understand only 0.0001%...

The main problem is, in my opinion, that a reasonable understanding of the natural world around us is impossible without formal training in mathematics. That's the main hurdle, the main obstacle. And math isn't easy.

maybe a little more than that. The problem is that there has been an explosion of knowledge over the past 100 years, and it continues at a rapid pace. It is difficult to keep up.