I get some trust from the fact that Telegram is the chosen platform for drug dealers and terrorists around the world. The metadata in Signal actually got people in trouble...
Whatever flaws Telegram got, it seems less impactful than getting mined by facebook and the practical design failings of Signal.
Telegram's clients are also FOSS. Anyway, I am not advocating for Telegram. Just stating my trust feelz with Signal and Telegram. I wouldn't use either for anything where my mere association would be a risk.
I think this may have been resolved now. However the issue remains that you cannot delete signal contacts and legacy groups, which means anyone who gets a hold on your phone number (without a pin) or phone, or account access to third party involved, got evidence for communication between you and a possible incriminating entity.
> Contacts must be blocked in order to be removed from your Signal Contact List. To learn how to block someone, click here.
You either have the contact in your contact list, or block list... I hope that's obviously supporting my claim.
Some of these meta data leaks may have been changed and are a result of my old account, however Signal lost my trust. (And lost sympathy over Moxy Marlinspike's opinions and presentation over time, e.g. the hangover/drunk "centralization: good" CCC talk, the F-droid drama, ...)
Whatever flaws Telegram got, it seems less impactful than getting mined by facebook and the practical design failings of Signal.