Does the US government want Google’s developers of the Chromium codebase to work on another company’s payroll instead?

Probably. The point is that google can't have any direct control of the browser as there's a conflict of interest between google's ad and other business and how web is developing. Take manifest v3 for example. Blocking content blockers directly benefits google's ad-business. Also removing support for third party cookies etc benefits google's ad-business while hampering others.