Grafana is much more focused on time series data - Datasette can handle that but it's not nearly as good a fit, since it doesn't do any rollups for you - you'd have to write your own SQL queries to summarize the data.
I imagine you could do that using SQLite window functions but you'd end up putting a lot of work in to get even a basic alternative to Grafana working.
The visualization features in Datasette are all provided by plugins - I'd love to people experiment with time-series visualization plugins which use SQLite (via the Datasette JSON API) on the backend.
How much overlap do you see with Graphana? Perhaps trying to target that group could yield more adopters?