I think, there are different aspects of quality. What you are referring to is the increased adoption of unit standardized techniques (unit tests, abstractions, continuous integration, etc). What the OP was referring to is the reduced understanding by the developers of why they are using each technique, and increased leanings towards just copy-pasting something from StackOverflow, or blindly cargo-culting something that a neighboring team does.

It is somewhat similar to all other economies of scale. Like AdWords, where you are one click away of being connected to thousands of ad publishers, but if the algorithm says "no", you get banned and will never get a chance to talk to a person. Like modern electronics where you can buy a device assembled in Philippines from parts made in China and designed in the U.S. for a fraction of a price of making it locally, but if a single $0.08 capacitor blows up, you're stuck throwing the entire thing out because the pipeline is not optimized for repairs.