Although the discouragement of “eggs in one basket” is a poor one, as the efficiencies gained in one step, can potentially be diminished or even taken away through having to build, maintain, and operate abstractions which are responsible for the platform that allows for spanning of workload placement.
As not all hosting providers will offer the same functionality, and through having to build your app atop a common denominator of functionality will prevent the business from realising the full potential offered by any one provider.