Is there a reasonable alternative, though? Email addresses? Adding a cryptographic challenge to prevent somebody from generating tons of accounts?
As far as phone numbers go, I'm not a big fan of Signal having them, but I definitely prefer not having to give them out! That change is a huge deal to me, as I can now communicate with people without handing them a phone number. And Signal has provided their client and server source code, along with evidence that their servers store absolutely nothing.
Nowadays, the most likely way your Signal data will get leaked is if somebody screenshots it.
Jami doesn't require a phone number, which is p2p. Xmpp (+ Omemo) doesn't require a phone number and it's federated... I mean, if a service is willing to rid of phone numbers, it'll do totally without them.
The challenge of having your device solve a nasty PoW that takes minutes would not deter most people: a timer once is better than evil captchas, phone numbers, etc. I don't understand why they use hCaptcha and not that.
phone numbers for spam prevention are a bandaid for a mediocre solution. the mediocre aspect being that it's totally centralized when it should at least be federated like SimpleX. SimpleX is the ultimate solution to be honest with you, it's federated, fast, extremely private and extremely secure.
If anyone knows how to get the beta without having to join the beta programme on Google Play please let me know; my phone is degoogled. They do have an apk on their site but it's not the beta.
You still need to put in your phone number to use their increasingly limited service though. Either go full bare sms/RMS integration or go full anonymous username only. This half ass approach please no one.
I still cannot comprehend their logic for why having full SMS integration would be such a disaster. It just makes no sense and I wish they'd admit that it isn't a security concern but is just that they don't want to do it. They just don't want to, and don't care that this policy makes it harder for users to adopt and use their service.
I know that SMS is a US-specific thing. But at least in the US, most people regularly interact with SMS. Having a platform that supports SMS means you can basically live in that platform -- this is a major part of the success of iMessage.
The idea that it would create huge security gaps... I just don't believe. I think the kind of user who wants to be on Signal clearly understands that SMS is not secure. All they need to do is have a clear visual indication when you are texting instead of using Signal, which isn't that complex.
Instead, people like me who might try using it as their primary platform just see no point. None of my friends use it. So why should I even have it installed? And none of my friends see a reason to install it because I and everyone else don't have it installed. If I could use it as my SMS app I might have it installed and lived-in, which greatly lowers that barrier.
They've definitely said, albeit relatively quietly and sparsely, that SMS/MMS messages have always been a headache to implement and maintain. It makes sense, although it sure as hell frustrates me too. It's harder to sell somebody on an app that only works on a proprietary messaging network, whereas old Signal could be sold to friends as "a texting app that can be encrypted" or "does big files".