I have many friends from Egypt, China, Brazil and other places but I live in Germany. If I visit Egypt in 2 years for some reason I want to shoot a message to my friends there to meet them for "a coffee face to face". There is no better service then facebook to enable this.

This has been discussed before; "better" != "only".

If the target is to have a contact, an email or a phone number are sufficient.

Also, it's fallacious to think that emails/phones are subject to change, while a Facebook account isn't - some people close it. Especially emails nowadays are used for a lot of services, so people stick with them for a long time, more than the past.

Email, text, phone call, all better messaging services than Facebook.

As has been said before: e-mail. I moved to Canada from Spain but go back from time to time, on holidays. Every time I go, I pick up the list of people I want to see and send them an e-mail. Has worked every single time.

  WhatsApp

You know that's still Facebook, rrriiiight?

True, but it does have end-to-end encryption so their ability to leak or abuse your data is a lot more limited.

I doubt they'd need the word "coffee" to infer what's happening when said message gets sent. Who sends it and to whom would be just enough thank you very much...

But they get all your location data. They'll know that you met for coffee.

Is it necessary to give them location data to use the app?

They'll know through your IP.

they will know that this IP sent this much data to that IP but not what was inside it.

Your ISP knows the same when using a web site via HTTPS. They can see you send a request to the website but not what it contained.

You could also use a VPn or TOR if you want to hide your IP.

And they'll know who you contacted and when. That allows for a lot of things to be guessed. Especially with hundreds of thousands of messages per user available to them.

Yeah, but my ISP has to follow the local laws and I can easily switch ISPs if I dislike my current one. Try that with Facebook.

Yeah, I might use a VPN but I'd also have to force all my contacts to use one as well.

As said by others, there are differences. Also, I set Whatsapp to never receive my location data.

But yeah, the networking effect is real. Whatsapp is what everyone uses, so far it seems like a decent compromise based on end-to-end encryption.

The data may ultimately belong to Facebook but Whatsapp is not the same as Facebook.

But everything is made by Facebook, the only difference is branding. It's like saying that Facebook Messenger only belongs to Facebook but isn't Facebook.