That is a very large company if you have a singular 40 million line codebase, maybe around 1000 engineers or greater? Network builds also takes significant investment in adopting stuff like bazel and a dedicated devex team to pull off most of the time. Setting up build metrics to determine a build decision and the other benefits that come from it is a one month project at most for one engineer.

It's like telling an indie hacker to adopt a complicated kubernetes setup for his app.