Retention-focused analytics for mobile apps

Retention is considered one of the most important metric. Yet current analytics give us just a simple "retention-triangle-chart".
Am I the only one to think there's something missing here?

What features I can imagine:
• "Age-buckets" - see how many users you have that has been using your product for over a month.
• "Activity-buckets" - see how many users are low/medium/high active (measured by sessions time, how often they come back etc)
• Easily set up email automation to reach out to the most active users ("talk to your users!").

What do you think? Are you also missing more details around retention in your analytics?