Comment by alerighi

Yea, how can we talk about privacy of a service that I need to register with a phone number (and in my country to register a phone number is obligatory to give your ID and signature, you can't activate a SIM card anonymously)

Centralized services should be avoided for a multitude of reason, the primary one is being dependent on some company that offers you the service and can and probably will shut down one day, with the result of loosing all the things you had on that service.

Look at the past, how many centralized services closed down and we lost all our data? Instead decentralized services are still up and running: email, usenet, IRC, even if unfortunately a bit forgotten these day (with the exception of email, even if most of people uses GMail anyway so it's in fact centralized...)