I sympathize with the sentiment, but the vast majority of my contacts already use other messaging systems that are identified by phone number such as SMS and WhatsApp—they don’t even use email, at least not for “text messaging”‐like things. In practice I’ve found that Signal has been the most successful privacy‐respecting messenger that my friends communicate with, which I attribute in large part to its policy of populating contacts lists by phone number, as well as its fad‐chasing features like stickers and GIF search.
After they announced removal of SMS I installed Johann's fork after few years (been using it for few years before but gave up with extended family after PIN nag screen fiasco which was last drop) to use it as SMS app only to find out that Signal is still missing such basic features as select multiple threads at same time and Archive or Delete them, you have to do it one by one, reminds of days when users for years requested basic feature to send more than one photo at time. Signal is total UX failure. I use it now just for SMS and didn't promote it to people to contact me, anyway there is basically only one person which I don't have on other messenger anyway.
so you like to run around and force all your contacts onto a new better messenger du jour? Messaging is by definition a social activity, so unless you sever most connections and just message yourself, you do end up using whatsapp, telegram, shit some of my family still uses skype! so all this well-meaning advice "just use..." is ridiculous in practice.
This fragmentation of the communication space is the problem that the new EU regulation for messenger interoperability tries to attack. I agree with this idea and also with the idea to make it mandatory only for platforms above a certain size.
To me it makes sense. We had centuries where people could send a letter from one country to another country, both with their own postal services. Why can't we send a message from iMessage to Whatsapp without installing another company's spyware?
However, I do not agree at all with the EU's plans for Chat Control.
Pondering why your refactoring of "Network Effects" has a lot of truth;
The supposed property that the attractive influence of a network is
proportional to its size, rather like gravitational agglomeration,
turns out to be largely false in practice.
My observation is that people don't join a network because "all their
friends" are on it. That's a myth. But they do find it hard to leave
because one or two highly weighted friends (family, parents living
abroad etc) are on it.
You could probably say "network effects is just marketing" too. I
think the idea of "organic growth" is also largely a myth. Massive
amounts of marketing hype and billion dollar influence operations herd
the masses, and also default settings and bundling. It's hard to avoid
Google, Facebook or Twitter when your phone and browser come
pre-configured with them.
In English that translates to "Don't use messengers that ask for your phone number and don't use messengers that aren't E2EE" => "Use messengers without phone numbers and with E2EE". So no, I think your weaker condition is not as good. E2EE is a good thing.