He'd then have to convince everyone else he wants to talk to to use Signal instead of Facebook. That's the hard part.

Install both? Migrate one friend at a time, starting at the ones you speak with most.

But then in this hypothetical scenario you’ve side loaded Facebook and it’s doing who knows what on your phone.

It’s not as hard as what people think.

You just tell your friends that you are not reachable on Facebook anymore and how you can be reached.

You don’t have to "convince" anyone.

Your real fear is that people will stop reaching you if they don’t want to install another app, send you an SMS, send you an email or to call you on the phone.

Well, if your friends stops reaching you because you uninstalled an app, honestly it looks that they are more acquaintances than real friends. And it’s ok. But it’s also ok if they are just an entry in your contacts list.

You’re making an awful lot of assumptions about how people think and behave en masse. When facebook is the primary communication factor for huge family groups, if you’re the only one not participating then you miss out on all those conversations. It’s not just about one on one communication, it’s about a virtual family presence.

I say this as someone who despises facebook but this is the reality we are in. Similarly, in most nations outside United States, you really cannot get rid of WhatsApp. If you don’t use WhatsApp, you are missing out on how much of your society operates.

It's not about being reachable in a 1-1 chat. It's about being excluded from group chats which are very important for keeping up the group and friendship in general. For example, if I deleted FB Messenger right now I would still get invited to the occasional event but there would be way fewer "yo, I'm at X, is anyone free to hang out?" type messages that I will see, or invitations from acquaintances in big group chats, or the current shitpost of the week that will become part of everyone's lexicon for the next 2 months other than yours, etc. For a lot of people (including me) such communication is a majority of their overall communication with their friends and breaking them does break a big part of their life.

I was under the impression that Signal was widely popular in SE Asia.

Unfortunately, you were mistaken.

Cool. Does signal allow you to register without a phone number yet? Data-only plans with no phone number attached are quite common in some countries.

By providing Signal with any phone number at which you can receive an SMS or text message, you can register a Signal account at that other phone number. For example, you can create a pseudonymous Google account, register a Google Voice VoIP number, and use that as your Signal number. Or you can even use a free throw-away SMS account and use that number when you sign up for your Signal account instead of your real phone number. The Signal service will happily send the throw-away number a text message with the verification code, letting you complete the account sign-up process.

Orrrrr Signal could just fix their shit. Requiring phone numbers for this long is borderline suspicious.

Registration also works for numbers that can receive calls but not SMS. Like any landline you (even temporarily) have access to.

Does that work if some else has used that phone number to register an account already?

Not if you enable PIN locking (and the account is active).

https://support.signal.org/hc/en-us/articles/360007059792-Si...

Telegram allows you to register without a phone number, as of recently.

Not yet, no.