It seems useless to me, at least regarding the cybersecurity aspect. Of course, it’s helpful when people ask for my contact information, and I don’t want to share my phone number or email address.
But they still require information that could be used to prove or be linked to my identity for registration, right? This means a hacker could still reveal your IP address, phone number, email, and your passcode. Likewise, the development team can access these as well.
I know I’m overly cautious about my privacy, but that’s just how I am.
All the personal information you mentioned should be hashed or encrypted. For any given phone number, see how little information they have: just an account creation timestamp and a last access timestamp.