I see Influx pop up a lot in communities like Home Assistant for doing time series data collection. I'm using Postgres for that myself (not a great experience but I knew that when I was too lazy to find alternatives during setup) but people seem very pleased with its performance.

I imagine similar dashboard services that don't necessarily work well in Prometheus are a good market for these types of databases. Prometheus is nice, but I don't think it's suitable for all Influx use cases (and vice versa).