I get the sense the name is being used in a general way like a “Karen”, but I’ve never heard of a “Brent”.

Brent is the engineer building all the real tech that a company in the Phoenix Project is building, and when the MC (a manager, Bill I believe) realizes this he re-directs resources so Brent can do his job without interruptions, ultimately saving the company. Excellent read, it's the first book managers are told to read when they use SCRUM/AGILE incorrectly.

From The Phoenix Project: https://allengeer.com/how-to-handle-brent-in-the-phoenix-pro...