Statistics can be especially useful for saving arbitrary information, not just information from sensors. For example, invoice data.
One way to store this information could be with a service that allows us to define the name of the statistic, date and value.
date: 2022-04-01 00:00:00
Ideally, if said statistic does not exist, it should be created automatically, although it could also be interesting to create it through a helper.
In this way we could store very valuable information in HA and take advantage of its power to make graphs and automations, for example compare bills year by year, or control our weight by pointing it manually if we do not have a smart scale.
It can even be interesting to save tasks carried out such as the last time the car was serviced and to notify us when a certain time has elapsed to do it again.