Each company wants to earn by using your data, and Signal doesnt allow that (but it can be backdoored). No company like google, apple, microsoft,... is going to give you application where they cant intercept the content.
The question at hand is whether any major company would allow consumers to send messages the company can’t harvest for data. The answer is yes. Apple does.
Are you saying they don’t? —That they actually have backdoored their E2E messaging app already?
If you are just saying that it’s not entirely impossible for them to do backdoor, I don’t see what bearing that has on the discussion.
Apple does, but as far as trust goes, they are on the same level as WhatsApp (also E2E).
You’ve actually got one set of keys for each device you add to iCloud, and each iMessage is encrypted independently for each device. So if you have two devices — say, an iPad and an iPhone — each message sent to you is actually encrypted (AES-128) and stored on Apple’s servers twice. Once for each device. When you pull down a message, it’s specifically encrypted for the device you’re on.
The thing is: it is valid to trust a company to keep their explicit word. That’s a different issue from trusting a company who never explicitly said they wouldn’t listen to your data: companies can be held liable for these sorts of public statements. If Facebook silently (knowingly) subverts Whatsapp E2E, they’re in trouble. But reading regular Facebook messages for ads? Storing them plain text? They never said they wouldn’t.
This is why Apple explicitly stating they E2E iMessage is a data point with value. It is valid to trust Apple more now, simply because they’ve upped the stakes for themselves.
Compare this to a bar bet: someone makes a claim, I am sceptical. They say, honest! Still sceptical. They say ok, bet you £300. I suddenly am much more inclined to believe them. No money changed hands :)
Before you start downvoting spree, read this:
For Apple: https://mashable.com/2013/10/17/apple-nsa-imessage
http://bgr.com/2015/08/06/iphone-fbi-imessage-facetime-backd...
https://www.tripwire.com/state-of-security/latest-security-n...
For WhatsApp: https://tobi.rocks/
(encrypt data with random key with symmetric encryption algorythm (AES,...), which is then encrypted and stored with the mesage twice. Once encrypted with recipient public key (asymmetric: RSA,ECC) and once encrypted with apple public key. This way you can say that you are having end to end encryption while you can still read everything and you can also use all the nice words in marketing material, AES, end2end, RSA/ECC,...).
I will tell you another case: Skype. It had a p2p protocol, highly encrypted and obfuscated, also the application was armored. The communication wasn't going through Skype servers but directly between devices. Once Microsoft bought it, the next version was using Microsoft servers and p2p was gone. Interesting, right?
Open source. And for really impossible also open hardware.