Homebrew only ever writes into `/usr/local`, which was unused by macOS until very recently (though unfortunately a few third-party tools also use it and lead to very occasional conflicts with Homebrew). The original rationale for using `/usr/local` over `/opt` was that, at the time several widely-used software packages had hard-coded installation paths and would require extensive patching to work in other locations [1]. This hasn’t been true for a long time though. On systems with Apple M1, Homebrew finally made the move to `/opt/homebrew`.
> and did weird root shit
On the contrary, the philosophy of Homebrew is that package installations should never require superuser privileges. The only time Homebrew does “root shit” is when initially setting up `/usr/local` writability. Not weird at all. Though it does mean that Homebrew is effectively unusable (and a very bad idea!) on a multiuser system.
Homebrew only ever writes into `/usr/local`, which was unused by macOS until very recently (though unfortunately a few third-party tools also use it and lead to very occasional conflicts with Homebrew). The original rationale for using `/usr/local` over `/opt` was that, at the time several widely-used software packages had hard-coded installation paths and would require extensive patching to work in other locations [1]. This hasn’t been true for a long time though. On systems with Apple M1, Homebrew finally made the move to `/opt/homebrew`.
> and did weird root shit
On the contrary, the philosophy of Homebrew is that package installations should never require superuser privileges. The only time Homebrew does “root shit” is when initially setting up `/usr/local` writability. Not weird at all. Though it does mean that Homebrew is effectively unusable (and a very bad idea!) on a multiuser system.
[1]: https://docs.brew.sh/FAQ#why-does-homebrew-prefer-i-install-...