Signal still require that you use a phone# to sign up

Your statement was that phone numbers make users identifiable. If they don't have my phone number, how can they use it to identify me?

and that you keep owning and paying for that SIM over the years

I don't know if you've noticed but it's nearly impossible to exist without a SIM these days. You can't even access your bank account remotely. But I suppose you only have a home phone and don't have internet access outside of WiFi?

in order to be able to verify it at random intervals...

in many cases around me, people who opened Signal accounts with some SIM card some day later traveled abroad, changed life, etc... and one day were asked to verify their account.

You're lying. You don't need to verify it at "random intervals", you only need it once when you initially sign up. You're just spreading misinformation at this point.

despite being a very anti-privacy feature

It's not, but please do elaborate.

funded initially bu US gov

You know what else is funded by the gov? TOR. But I suppose that's compromised as well? Which also compromises many of the messengers using the TOR network?

I don't support phone # verification, but they do have valid reasons for it, and it doesn't compromise the service at all, as you claim, because the only things tied to your phone number is:

1. When you first registered
2. When you last connected.

Which isn't really super useful information to the gov. And in order to get that info they have to ALREADY HAVE YOUR #. Which, of course, they do already have everyone's #. It's not exactly private information.