Right. But you need tooling to manage those dependencies, and an ecosystem of content to avoid reinventing the wheel. That's what containers provide. Since Bazel predates the modern container ecosystem, it had to invent its own tooling. The user experience is very rough, and the ecosystem tiny. As a result most Bazel users do not run their builds in a controlled environment - see the parent blog post.

Adopting containers would solve this, but it seems to be a major blind spot for the Bazel community. My theory is that for them to adopt container technology, they will have to reinvent it themselves, hence my tongue-in-cheek comment.