Having ezpublish.api.repository (and API services) lazy will allow to avoid ServiceContainer injection or lazy closures (e.g. ezpublish.api.repository.lazy).
This will also avoid issues like EZP-22116 when helpers depending on API services are instantiated by other services as dependencies, but not really used. Without lazy services, it forces a connection to the storage engine.
In other terms, this can avoid a lot of empty dbParams issues.