There are no such guarantees. People failed to choose a protocol that is trustworthy and fell for pseudo sometimes-on encryption. He is trying to make money while the market is going down.
I wanted to object (as a happy Telegram user) that I want to preserve message history for all my devices, but then it occurred to me that iMessage is end-to-end-encrypted and also has pretty transparent message history sync.
So now I think that yeah, Telegram should adopt E2E by default.
Another thing that would be lost with the switch to E2E is server-based search, but honestly I can live with that.
>I wanted to object (as a happy Telegram user) that I want to preserve message history for all my devices...
Telegram is already useless on that score. Since the other party/ies in a conversation can delete their messages from everyone else's devices as well as from their own. I stopped taking any of Telegram's privacy and security claims seriously when i discovered that gem.
I still use Telegram to keep in touch with a load of family and friends but I have no faith in whatsoever any of their self-righteous privacy & security claims and comparisons with other messaging services. For a very long time now, evey update has focussed on adding moronic cutesy junk like animated emojis and stickers. So it's quite clear that their focus has moved away from being a private & secure messaging service and towards appealing to the TikTok generation.
That's fine. It's their project. They can do what they want with it and [as I said] I still find it useful. I just wish they wouldn't keep on trying to convince people it's a serious secure commmunication tool.