I disagree. There are internal parts of the application that benefit from tracing, and if you are using the OpenTracing standard, tagging your traces with metad

I disagree. There are internal parts of the application that benefit from tracing, and if you are using the OpenTracing standard, tagging your traces with metadata can allow correlations in the data to stand out (something LightStep is good at). Tracing at only your edges wont help you discover that requests get slower for customers with some subset of features enabled with given settings, for example.