With WhatsApp or Signal, if you want to talk to a stranger (e.g. if selling something) you have to share your real number, while in Telegram you can share just a username.
To coordinate my own anonymous commodity transactions I just use gpg to encrypt a .txt which can be delivered in all sorts of anonymous ways. I can't say that I transact anonymously too frequently though, so the additional friction with this method isn't especially onerous.
But why not just use an email address or something for that case? I get how it would be ideal (and myself desire) to have one messaging tool which works in all cases, but it doesn't seem like a massive failure specifically of Signal to not work for this usage. Certainly not one large enough to warrant the torrent of comments I see any time Signal gets mentioned on HN
I regularly talk to Chinese vendors selling robot parts who want to talk over WhatsApp. This is ultimately fine for me but it’s an example of a scenario where I don’t really want to give anything more personal than necessary.
Sure that makes sense to me, however I will say that if I was a vendor selling stuff internationally I probably would want (and even require, depending on export controls) some level of de-anonymization on the buyer's part. Presumably at the very least you need to provide a shipping address to receive the goods, which is no less identifying or difficult to spoof than a phone number.
Whatcha selling :)
To coordinate my own anonymous commodity transactions I just use gpg to encrypt a .txt which can be delivered in all sorts of anonymous ways. I can't say that I transact anonymously too frequently though, so the additional friction with this method isn't especially onerous.