How does whatsapp make money? (At all, and how much?)

It's not possible it makes as much as the main Meta properties. It has no ads on anything people use.

It's not about money - how valuable the company is depends on how many people use it intersect how useful it is. As long as it's valuable, it's valuable.

I suspect WhatsApp has a better shot at being the "everything app" compared to Twitter.

Am guessing they want to become like "wechat"

They have a business api and take a cut of transaction fees on whatsapp pay.

And they obviously cross-reference the data with Instagram/FB to sell you stuff.

Meta does not have access to your WhatsApp chats as they are end to end encrypted.

Maybe not but they have all the timing info, the identities of the chat participants, and the facebook surveillance network. They also used to leak URLs pasted into the app out in order to generate previews, so they know what you’re linking to from within the app. Us they can infer way more about you than seems obvious at first.

As long as you and the recipient has encrypted backups turned on How to enable end-to-end encrypted backup[0]

[0]: https://faq.whatsapp.com/490592613091019

No, those are Backups stored in iCloud / Google Drive. Google / Apple have access to those, not Meta.

They are no longer end to end encrypted if google/apple have access

They are encrypted to your device and your device can upload them unencrypted in backups if you don't configure encryption. Plus the original argument was Meta did not have access.

Same in all of South America.

I have a great idea of Whatsapp's marketshare globally. I am simply pointing out the ad revenue of Whatsapp is extremely low compared to their other properties. There is simply not enough surface area in Whatsapp used for that and their business profiles etc. are not going to be outearning US users of FB/Instagram.