Signal allows my (non-technical) friends and family to help raise the bar while providing a chat client that offers basic calling features.
Signal isn't about being perfect (it's already made tons of concessions that make it useless to anyone "serious" about privacy). Instead, it helps raise the bar against bulk collections.
Except the parent is right, if you don't have metadata protection by default, then it is no different than running something that's federated but secures it's transport or secures its payload end to end.
Bulk collection concerns the envelope, knowing who you spoke to and how long for is _exactly_ the kind of information NSA was tracking 5 years ago. Content was never the issue, content can be encrypted by default with non-centralised systems. What's the point of a centralised system now, that was its only justification.
If you have a Trojan on your phone that steals all your call info, remove the Trojan instead of not calling people. If signal isn't seamless and doesn't provide a good experience, nobody will use it, making it useless. If you don't want Apple to track your calls, get an Android phone or disable iCloud. What are you doing with iCloud if you're privacy-conscious, anyway?
Signal isn't about being perfect (it's already made tons of concessions that make it useless to anyone "serious" about privacy). Instead, it helps raise the bar against bulk collections.