Statistics, Recorder and InfluxDB

Hi everyone,
I am very confused about the long term statistics and InfluxDB. I installed InfluxDB because I thought, that information is purged after 10 days. Now I found out that Homeassistant keeps statistics longer than that. So… what would I need influxDB for?
I think that one-hour-snapshots are more than enough for the long term statistics I want to use.
Before I deleted InfluxDB I wanted to check and went into history and looked at a person and a temperature sensor. Both didn’t have any data after the purge days.
What am I doing wrong? Does InfluxDB kill the statistics of home assistant?
Did I interpret the long term statistics wrong or does the history graph not show the long term statistics?
I tried to use the search, but I didn’t find anything.