I use homebrew on Intel and a couple of Apple Silicon Macs. I never used root, or sudo to install homebrew, or any packages. In fact, since the packages are written and installed in the /usr/local (Intel) or /opt/homebrew (Apple Silicon) directory trees that should be owned by you, with group admin, no dialog has ever appeared requesting my admin password for any purpose. Only Layer Four Traceroute (lft), recommends sudo usage when run, and explains why.
Yes, there is an element of implicit trust involved, but there would be with any third-party package management solution, whether that was conda, npm, Perl module, Python module, Ruby GEM, etc. Apple is well on its way to eliminating the latter three. Homebrew installs its own portable Ruby in order to effect the package maintenance process.