Homebrew has basically reached the point where it's "critical infrastructure" for macOS devs, and it would really be a damn shame to see it slowly fade away just because the creator has moved onto other things.
Homebrew is critical infrastructure, which is exactly why it shouldn't change dramatically.
Now, if GP has lost interest in the project, or doesn't have the time to keep it running satisfactorily, I'd definitely agree with you - but I didn't get that impression from his post.
There are better alternatives, even, that are a quick and painless install process away. For example, nixpkgs is competitive with it, and does not include the Google phone-home supercookie tracking spyware that is on by default without consent in every Homebrew installation, and works great on macOS.
Homebrew could disappear tomorrow and nothing extremely bad would happen. That can't be said for the power grid or water system. Tossing around the term "critical infrastructure" for things that are important but very sub-critical is hyperbole that waters down the (important) term to meaninglessness.
I use Homebrew every day. Thank you for the the incredible work in keeping things ticking along. And congrats on still enjoying it!