I’ll take a snippet from my blog post https://akoutmos.com/post/phoenix_live_dashboard/ as I covered this exact point there:
While LiveDashboard is an amazing tool, it is important to understand when you should/shouldn’t use it and whether or not it replaces any of your existing tools. To be clear, LiveDashboard does not replace your ELK or Prometheus+Grafana stacks. Those are purpose-built logging/monitoring tools with purpose built databases to store the data that you can query (see Structured logging in Elixir using Loki and Prometheus, PostGIS and Phoenix Part 1 for details on those topics). LiveDashboard on the other hand, does not actually persist any timeseries data or index any log messages. Instead, its focus is on presenting real-time logs and metrics to you whilst using the tool. When you close LiveDashboard, all the data captured during the duration of your session is gone.
If you are looking for something that is free (money wise), I would point you towards Prometheus and Grafana. They are both open source and well supported in the Elixir community. Check out my two part series to get some insight into setting up those tools:
Hopefully that helps!