yeah, that means not encrypted. When speaking to a web server, you are one end, and the server is the other. Tls ensures that there isn’t a man-in-the-middle.

In case of telegram, you are one end another user is the other end. Telegram themselves are, by design, a man-in-the-middle in this case. I’m not concerned about a different middleman intercepting communications between me and telegram. I’m concerned about any middleman (which includes telegram themselves) intercepting communications between me and my friend.

So no, telegram chats are not encrypted by default. Telegram can read them.