Depending on how technical you are, similar visualizations can be produced in Google Sheets/Excel or Metabase.
The issues are: 1) exporting/importing the data (manual CSV, via API, sourced from an existing DB, etc...) then 2) knowing which questions to ask and how to visualize answers to those questions
You could also code a custom dashboard using something like D3.js
A bit of self promotion, though not opensource. If you store your data in sheets, Probe Sheets plugin [1] calculates basic metrics based on some basic data: customer id, mrr, start and end time of subscription. We do not store the data you send (there is no way I can prove that to you though, but you can always obfuscate it somehow)
The issues are: 1) exporting/importing the data (manual CSV, via API, sourced from an existing DB, etc...) then 2) knowing which questions to ask and how to visualize answers to those questions
You could also code a custom dashboard using something like D3.js