Homebrew the package manager is quite popular but that doesn’t indicate that it is engineered well. For instance, it doesn’t work with multiple user accounts which is such a trivial thing!
Sorry, but I’m failing to see how rootless containers are relevant.
Having multiple user accounts is a legit use case - think e.g. a shared device. A typical Linux package manager’s install is a privileged operation. Homebrew on the other hand gives the user that had originally installed it write permissions to certain directories. This strategy enables sudo-less brew install for the specific user and prevent it from being used by anyone else.