alt Hacker NewsTelegram is not E2EE because it's easier and faster to sync and transmit messages between millions of people. The scale of Telegram groups and channels is massive. Telegram, for a long time, has not complied with law enforcement requests and has made it hard for authorities to get data because of their architecture. You still have Secret Chats for E2EE messaging as an option.
Not sure what your point is. Telegram is not an example when it comes to privacy. Anyone who has access to the server has access to pretty much everything. Nothing can tell you that governments (or bad actors) are not already reading your Telegram messages.