[latch]

Because smaller shops want the benefit of monorepo without paying the cost/discipline it requires. Mono repos without excellent unit tests and integration tests, review processes and various tools, is a disaster. And, in fairness to Google and Facebook, when they talk about the benefits of monorepo, they always mention these costs (it just gets ignored by people: Headline Driven Development)

And I'm sure that the number of companies doing really good integration tests in somewhere in the 1/10000 range (or worse). Every dependency, external provider, internal API, data store, taking into account versioning....it's hard.

I'm a huge believer in automated testing, I've written about it and done it for almost two decades now. My views on it have continuously evolved...and comprehensive and effective integration testing is still a complete mystery to me. The only reason I'd want to work at BigTechCo would be to learn about that specific aspect of software development.