Site Builders are an important part of the Drupal development cycle.  They usually know Drupal better than developers!

Drupal Recipes - Composable Configurations for Drupal Websites

Media Image

I have never been a fan of distributions in Drupal.  They can be hard to keep updated, cannot be retroactively added to a site, do not allow mixing and matching of features, and you're often at the mercy of the distribution maintainers.  As such, all of the Drupal sites I've built in the past few years are Core and Contrib, with a smattering of Custom development when necessary.