Ultimately Being autodidact is about creativity. The difference between predictable ways of doing knowledge and autonomously chosen wyas, is what differs institutionally taught thinkers and self learned. Creativity and self created order is a double edged quality. But only a moron will say that predefined order is always better.
Autodidact is about enjoying learning and thinking. When you are free, you tend to learn with joy. In enjoyable ways. You choose the most interesting subjects and so on.
Ultimately, the more you enjoy the process the more productive you are. And more creative ( good mood breds ceativity, research shows)
Self study has more relevance. You have no system to force you, so you gravitate towards what is naturally most interesting. Which is usually the more relevant questions
More practically oriented.
Better odds for interesting findings. Much of academ is about doing thing is a quite known way. Hence, many people act similarly and may get incrementally better results, but not much unexpected breakthrough. Autodidacts have better chnaces to find really new things (steve jobs was thinking differently)
No domain insulation. Much insights come from combining different fields. Autodidacts are less field secluded.
Do not listen to phds about this
The self interest of the phds is against autodidacts. Every critic of this that has a phd, is suspect. As he has a strong self interest to exalt the value of his institutional (and overvalued) "knowledge"