Yes, but the brain is an extremely complicated thing. Data was just released showing 3,300 new types of brain cells. This is relatively new information that was likely only discovered with newer technology. (In some cases, we knew about these cells, but they were ignored as irrelevant.) Even without mentioning psychedelics, it's going to take us years to understand how the brain functions.

To your point, we could have been so much farther ahead with our research and understanding. It is actually quite depressing to think that this kind of research was restricted because of politics.

FWIW, I am a massive supporter of using psychedelic treatments. From my own use, I believe I was able to completely break out of nasty cycles of anxiety and depression. It's not for everyone and it has its own risks, for sure.