Facebook is the king of online tracking. It is present everywhere, literally everywhere, in the form of sub-frames, sub-resources, comment boxes, SAML logins etc. In iOS, it collects device id, user id, name, phone number, email, physical address, device attributes, device signals, nearby access points, Bluetooth, everything. Facebook not only tracks what you are doing on Facebook or subsidiary applications, it also tracks user’s off-Facebook activity. You can check your off-Facebook activity here.
Now check the current version(applicable from Feb 2021).
Can you spot the difference?
WhatsApp collects the similar data that other three applications of Facebook does. Now Facebook will have access to the your WhatsApp information also.
Telegram is an open-source free messaging service that runs on donations. It doesn’t collect data to serve ads, so, from the data privacy perspective, it is quite safe. It doesn’t have end to end encryption for all the messages, which might be a point of concern for some people. The application collects minimal amount of data which is required only for improving the application.
After going through so many policies, I will definitely start trying to avoid application which collects data more than required, to safeguard my online experience. It is always the choice of an individual in such cases. Take wise decisions, stay informed, stay alert. Wish you a very happy new year.