> that simply isn't the attacker model most people have: they want the people they are talking to to not have their real phone number / real email address, and couldn't care less if Telegram or Snapchat or Google or even Facebook knows who they are taking to
Are you sure you're not extrapolating from your needs to that of "most people"?
I don't doubt that there are people for who need anonymous communication (whether just sender-anonymous or sender-anonymous, recipient-pseudonymous). But so far, I've never had the need for it.
Quite the opposite, actually: I wouldn't want to receive anonymous messages on Signal, at least not without opt-in.
No: I am not (in fact, I am really strange: I am a super famous person who has decided to have a single public phone number and email address that he gives to everyone). I think part of the problem here is that you seem to think leaning heavily into the anonymous communication scenario, but that isn't how other people conceptualize wanting to not have their real phone number or email address given to random people: the real play is almost entirely about being pseudonymous, where you might have your name (or a "well-known alias") and a photo of yourself attached to the account... but not a real phone number or email address (which tie your identity together to other systems). This use case is so common that even tech people whom I feel "should know better" opt for solutions like Apple or Facebook login rather than giving away their real email address to a random website!
So, first, to address this: it is frankly extremely rare to have a realistic attacker model that cares about eorher governments or a chosen large corporation having access to your chats, at least "in the West". Like, seriously: sit down and list who you think falls into this category... this is a list which starts with "political dissidents" and continues into some really strange low-likelihood scenarios, as the entire premise surrounds a government or law enforcement agency subpoenaing your messages.
Most of the people I know who are in this category are simply people who want to believe they will one day be targeted by governments for being too dangerous. I can still motivate this software for people, based mostly on scenarios involving bad people getting jobs at large companies to access your information (this is a big issue with Facebook), but even those scenarios barely work against companies like Google (which have good internal information controls). I have gone into this in more detail before (with someone shilling Signal who hilariously ended up just admitting that Signal doesn't work here as it is a "privacy issue").
The ironic thing is that, without also solving the untrusted contact problem, this set barely even includes political dissidents: I have tons of friends who do stuff like coordinate protests, and the #1 realistic concern is that the police--whom I also talk to a lot (I am an elected government official), and I know they do this--have managed to infiltrate their giant group chat and are just watching it all happen and writing down phone numbers. There is a big gap between anonymous and trusted, and it is where most use cases actually happen.
So, on the other side, pretty much every "normal" person constantly meets people with whom they want to communicate without giving away their real phone number / email address. How do I know this? Because that's what most people want to talk with the people whom they are casually dating. This is a big reason why everyone uses Snapchat for almost everything (and Instagram or TikTok for everything else): because it gives you a feeling of control over what people know about you.
Just earlier today I was watching someone on TikTok--in a video about dating communication--say "using Snapchat as the only form of communication during the talking stage is the move: I'm not giving you my phone number... we just met! I would sooner give you a urine sample" (this is an exact quote). The comments mostly agreed with everything she said (and she only had like three supposedly-"unpopular" opinions that were actually quite popular ;P); here are some of the strongest comments about the Snapchat mention.
> Yes! Snapchat! The only way they can’t use one type of social media to find you on other social media
> Yes about the snap vs phone number. I started online dating after a 15 yr relationship and I got a phone stalker that texts me with new numbers
> yeah idk why ppl hate on snap. I prefer it bc they don't have my last name or extra info on me and I can see more what they look like beyond a few pix
Were there people who disagreed with her? Sure, but they were all either advocating for refusing to leave the dating app in the first place (which is itself a trusted provider protecting you from untrustable contacts), were advocating for a different but similar solutions (that still don't involve giving out your phone number), or seriously said "I don't know if I am just old or what"... to which I will note "yes, you are apparently quite old :/".
> Snapchat is dead there are apps like Text+ that create burner numbers...that’s what I use
> Yeah you’re right about this but the Snapchat thing is enlightening as somebody who was an adult before Snapchat lol
Are you sure you're not extrapolating from your needs to that of "most people"?
I don't doubt that there are people for who need anonymous communication (whether just sender-anonymous or sender-anonymous, recipient-pseudonymous). But so far, I've never had the need for it.
Quite the opposite, actually: I wouldn't want to receive anonymous messages on Signal, at least not without opt-in.