I still disagree, but I think I better understand the disagreement now. I find it easiest to learn a new language by starting with the canonical beginner's book, e.g. the Pickaxe book for Ruby. I find it hard to learn tooling like CI/CD, logging/metrics, etc by reading or through personal projects, I much prefer to learn those on-the-job as necessary. It seems like it might be the inverse for you.
Even if a new codebase isn't exactly 'Effective Java' quality, it's good to have that reference to better articulate to yourself exactly how the codebase is flawed.
Even if a new codebase isn't exactly 'Effective Java' quality, it's good to have that reference to better articulate to yourself exactly how the codebase is flawed.