I think the fact that nobody in the west has taken a WeChat like "everything app" position might be a sign that it's not necessary or inevitable.
So then ... Why should they copy WeChat? As an exercise in and of itself?
The best answer I could come up with is "domination" and I don't think that's a good reason to do something.
That's not a requirement at all. You can message literally anyone on FB, conditionally - there 'message' button is visible (exception to hackers). You can also message Zuck, even though you may not be friends with him.
You can "message" anyone you want, except that if you aren't friends it will almost always fall in some weird secret hidden bucket that most people never look at, and is hard to find even if you try. If you share a direct connection it might go through, but in my experience not always.
YMMV! In the very recent times, I've sent countless messages to members in various Bronco groups and sellers in the marketplace, I've almost always got the response.
Messaging a random person does.
Point is I want a messenger contact list that is distinct from my FB friends list.
Isn't that exactly the problem? If I can't be reasonably sure that a message I send will be seen by the recipient, the messaging service is useless to me.
Try messaging someone Facebook doesn't think you have a reason to message. It will go to a different inbox that I bet half of users don't know exists, and even those that do check it once a year.
This is not the case in democratic countries. Most people treat financial transactions and public opinion as separate entities. Commenting on amazon is way different than commenting on twitter. Integrating twitter with banking account is not going to be successful.
While WeChat was adding features, such as an independent creator marketplace, or payment systems, Facebook spent time aggressively pushing online web games that almost killed their platform.
Then Facebook started going for attention metrics above all else, and it became an app that fed people stories that made everyone angry and depressed, but did a good job increasing engagement!
Facebook should have started cloning WeChat features years earlier than they did.
Facebook's other problem is their real name policy. Having to be friends with someone to message them seriously limits how many people I talk to through Messenger.
But as it is, Facebook Marketplace is winning. Facebook events is winning. Facebook payments, no, not sure how they messed that up. Venmo and a few others are duking that one out, heck Venmo is used at garage sales.
Facebook doesn't need hyper growth, they need to just keep current user's happy and coming back for things. It doesn't matter if they aren't the #1 destination for GenZ to post photos. If everyone is buying/selling used goods, and going to concerts, and arranging birthday parties, and posting a small selection of curated travel photos, then be happy with that, and keep expanding into adjacent markets.
And separate out "people I want to talk to" from "people I want to show my life to".