Why WhatsApp? It is closed source (Telegram has open source clients). It belongs to Facebook. And Zuckerberg doesn't look like a person who can stand against go

Why WhatsApp? It is closed source (Telegram has open source clients). It belongs to Facebook. And Zuckerberg doesn't look like a person who can stand against government, while Durov has been saying several times that he is not going to cooperate with any government. The disadvantage of Telegram is that it requires you to provide a phone number (and this is much more important than some rare cases when encryption could fail). It means you cannot stay anonymous while using it. If there is an error in Telegram server code then your phone number can be leaked. A messenger that cares about privacy should never require a phone number and should not have history enabled by default (because your history will be used against you as an evidence). As I understand WhatsApp doesn't match these requirements.