if that alone give you 100% coverage, 0 critical bugs leaking into production, that is sufficient for the size of app you may have, however in an enterprise setting where thousands of B2B customers with nuances in usage and customizations and 100s of permutation and combinations, that alone may not be enuf. actually with agentic code genration this problem will be exacerbated. so in my case I can tell having some linkage of production incidents and production logs back to tets plan and specs is essential to ensure zero critical bugs leak into production. these production incidents are gold mine for actual user workflows and data. A typical tester can only just anticipate how the real world user will use their app and test these scenario in a limited way, but production workflows and data if translated into test cases can enrich the existing testng suite and give you quantifiable end to end test coverage otherwise its kind of hope rather than a plan to have rock solid release.