It's much more convenient indeed, just be aware (I kinda trust that you, being on HN, already are) that it's all encrypted-to-the-server, so any sysadmin can read or hand over your messages. Choosing between known metadata gathering on WhatsApp and a potential Telegram data breach (intentional or unintentional), it's really a devil's dilemma for me.
Since a few months (now that Telegram has failed to deliver on the encryption promise and profit model for many years, making it a bit too shady) I've been moving more and more to Signal (after also trying Keybase, Threema, Wire, Riot/Element, Jami/Ring, and evaluating others), but man usability and features really take a hit with any of them. Enjoy Telegram, but be aware of the trade-off!