It's honestly not realistic to expect any free service provider to martyr themselves for your privacy. With that in mind, remember that anywhere you don't control the metal someone is watching you.
Sure, but Telegram has repeatedly made misleading claims about the privacy of their app and novel cryptographic protocol compared with alternative free services. The problem isn’t that Telegram disclosed data to lawful requests, it’s that (1) their marketing re privacy is at best misleading and (2) they had that data available to disclose.