Opposite end in terms of security. Telegram group chats have no E2EE, private messages aren't E2EE by default (you have to initiate it as a "secret" chat), and the encryption itself is home rolled.

Yup exactly, their home rolled encryption is problematic in and of itself, but the fact that it lacks E2EE means you shouldn’t even trust it in the first place.

Also opposite in terms of feature-richness.