If you can't trust the software you're installing, it makes much more sense to run it in unprivileged containers or VMs than relying on account-level security. If a malicious package is distributed via Homebrew, it can still do a lot of damage running as your current user, as any data or resource accessible to your user can be exploited or exfiltrated.
I tend to agree with what another HN member wrote about sudo/root and Homebrew: https://saagarjha.com/blog/2019/04/26/thoughts-on-macos-pack...