That's exactly what lots of early web frameworks did. One big yaml/ini file with every credential for every environment, and a single "environment" selection w

That's exactly what lots of early web frameworks did. One big yaml/ini file with every credential for every environment, and a single "environment" selection when launching the app. A truly huge footgun. In their defence, it wasn't as bad back then. They were created by/for small teams/sole practitioners with no separation of responsibility. Source control would be on-prem (or just local directory backups). The Java EE model with explicit separation between development and deployment as separate activities was a disliked, or not understood.