How can I be successful?
This is what Warren Buffett, would answer:

“You will be successful UNTIL you stop trying to be good at everything.”

Being a generalist is a TRAP!

Warren Buffett calls this the Circle of Competence.

Imagine a small circle WITHIN a big circle.
The bigger circle is what you THINK you know.
The smaller circle (inside the bigger one) is what you REALLY know.
This SMALL circle represents your area of expertise. This small circle represents whatever you’re an expert, where you easily stand out. Where nobody can beat you.
STOP being a generalist!