In other words, Telegram doesn't even deserve to be in the same conversation. Even if it had the best encryption out there (however you define that), that wouldn't mean anything when it's not used in like 98% of the cases (percentage pulled out of my ass).
It's like comparing Signal to Facebook's Messenger, and I'd still say Messenger over Telegram because at least it uses Signal's protocol under the hood (I believe the feature is called hidden conversations) instead of inventing its own thing and ignoring the expert opinions.
Granted I've never used WhatsApp, but I've been using Signal for like 5 years now on my phone and on my laptop with absolutely no issues.
It tries to have feature-parity to WhatsApp; looks the same, works the same. All this while researching innovations on cryptography that doesn't compromise user experience too much.
In my experience, doing exactly what WhatsApp does (but safer) makes it an easy sell to people around me.
Other than that it's definitely a great alternative.
Ever heard the first rule of encryption? "Never roll your own crypto". Well they broke the rule and they won't let anyone check if the crypto is secure or not.
Not to mention encryption is off by default and your plaintext messages are stored on their servers...
So I personally don't even know if I'll keep fighting for my privacy and stuff or if I'm going to give up now. I don't want to, but I honestly don't imagine how on Feb08 I will be telling people who aren't my close friends or co-workers, but communication with whom is really valuable to me, that I refuse to join any WhatsApp group chats anymore, so they will have to notify me about anything important (important to me, in he first place!) personally via SMS, Telegram, email, whatever. Especially now, when people are forced to communicate remotely and stuff gets cancelled/renewed/delayed because of another round of idiotic government regulations, so if I'll fall out of these communities, I'm pretty much left in the vacuum and won't know about anything that happens.