I think at this point it should be pretty clear that Signal never had the goal of anonymity which is an orthogonal concept to privacy. While I would support sign-up without phone numbers, it doesn’t address the same threat-model and there are many alternatives if anonymity is your goal.

But I want near-perfect privacy with usability, which Signal provides for me and all my contacts. Who cares if my government knows I use Signal, as long as they don’t know who I talk to and what we talk about.

Edit: just saw your other response. What you want to achieve, is almost impossible. Even if Signal doesn’t log who you talk to, like you assume, there are still methods to unmask this info. There are PoCs for things like timing attacks for notifications etc. which combined can narrow down the list of contacts significantly. But it seems like your threat-model doesn’t align with Signal goals which means it’s probably best for you to search an alternative instead of hating on Signal for not catering to your needs.