Without caching, you build and rebuild and rebuild the same things over and over. With caching, a less strictly managed stage, such as a routine PR build, can

Without caching, you build and rebuild and rebuild the same things over and over. With caching, a less strictly managed stage, such as a routine PR build, can affect high-stakes stages such as production builds. But if your builds are reproducible, and dependencies pinned, it should not make a difference. Old-school scripts have the disadvantage of being slower than a more nice declarative approach, be it makefiles or docker build. Both provide a way to trace the build process in detail; observability is key.