I strongly dislike this perspective and find it naive. It is similar to saying Mac is more secure than Windows. WhatsApp is a huge target compared to Telegram.

I guarantee you if we all switched to Telegram nothing would change, and I would bet money these exploits boil down to open source libraries which are commonly used in these apps.

It does not pay to be high browed with security. Even Chrome, with all its investment into security, gets pwned on a regular basis.