Lawyers run everything, not just the FCC. All the politicians are lawyers.
https://www.economist.com/business/2024/06/27/why-everyone-s... was a recent article about this.
Its pretty fundamental that all lawyering is actually about something else (be it injury, crime, real estate, divorce, etc), so lawyers get the idea of learning the basic / important parts of the subject matter, using an expert witness when necessary, etc.
It's the same with any senior management, they don't know the specifics of anything, that's what graduates/juniors are for, what they know about is products, politics, policy, relationships, etc.