I’d like to add to what @grant2 said, and also make a counterpoint.
While timeseries databases are a really good match for Grafana, they’re not the right hammer for every nail - even when it comes to timeseries data.
If you want to do joins across tables for example, you’ll generally want to use a relational database.
People often choose timeseries databases due to their performance. A modestly sized Influx instance, for example, can ingest hundreds of thousands of data points per second, and I believe Prometheus is similar. Query performance on large timeseries datasets can be very good also.
Since you said…
…my take is that you don’t need to worry about performance (or at least not optimize for it). If I were you I would make a decision based on (a) how you’ll be ingesting data, and (b) how you’ll want to query data. Regarding ingestion, both Prometheus and Influx have nice integrations with monitoring tools, so that may be a reason to go in that direction.
If it helps, a few people (including myself) have shared some thoughts on different databases in this thread - mostly relating to IoT use cases. There will be much better resources out there, especially in the context of monitoring, but maybe this is a helpful starting point.