Yup, we do all that, except the 10k developers scale. Ha.

I had the advantage of starting with fresh codebases and a small team. Obviously, adding this to an existing organization is much more difficult.

When you setup your system correctly from the start, it also becomes a great hiring tool. Once you show developers the environment you work in, mouths drop and they almost beg to work for you.

Doing it is hard, but not impossible. At this point there really is no excuse to not start things off like this. It is about 1-2 weeks of effort to setup a new project with all the right tooling on top of GCP thanks to the features they give you as part of their platform.