The main reason is, master branch protection rule in this repo requires pull-requests, approvals, CI checks etc, which is not suitable for goreleaser.

Second reason is, if we keep the formula in a repo with homebrew- prefix, s5cmd brew installation will be a single step, which is nice. For example, if we have homebrew-tap repo with a structure like below:

homebrew-tap
└── Formula
    └── s5cmd.rb

brew install peak/tap/s5cmd will directly install the package from the repo without tapping.

https://docs.brew.sh/Taps#repository-naming-conventions-and-assumptions