As someone whose week was ruined by an overwhelming proliferation of `--mount type=cache` options throughout a complex build system, I'm not so sure. Externall

As someone whose week was ruined by an overwhelming proliferation of `--mount type=cache` options throughout a complex build system, I'm not so sure. Externally managed caches don't have a lifecycle controlled or invalidated by changes in Dockerfiles, or by docker cache-purging commands like "system prune". That means you have to keep track of those caches yourself, which can be a pain in complex, multi-contributor environments with many layers and many builds using the same caches (intentionally or by mistake).