Its because people are sheep. And if you claim to be a guru and act like a guru, people will listen to you and follow you. It's really that simple. Just try. You can be a guru and earn millions. The only thing stopping you is that you are an ethical person who knows that the stuff will be incongruent. But if you can somehow get over that through either an act of god or being born in an environment where people treat you as special or just happen to get lucky few times etc you can be the next Cathy of your field too.

It's Cathie's Wood fund (the woman in the video is an "analyst", it's not Cathie).

How to they stay in business ? Marketing ! They know how to sell themselves and how to appeal to naive "investors" that discovered stock market during the post-covid bubble. She has also mastered the power of social media.

Also note, that she is making loads of money for her and her fund - through management fees. Of course it will stop eventually... but in the meantime, she will make hundreds of millions of $ in fees.