I too have some highly opinionated ideas about how time-series should be implemented, and after some initial attempts to get some power/energy/cost monitoring and consoles working in HA using helpers and automations, I’m of the opinion what HA has right now is barely fit-for-purpose. I suspect most people just don’t realise how bad/wrong it is and assume what it shows is correct.
To be fair, I don’t think there is a single timeseries DB I’ve seen that gets it right since RRD. They all make terrible mistakes in their core assumptions and are very inefficient. I have fragments of a doc scattered around that I should pull together and turn into a “how to do a TSDB right” document.
However HA’s attempt seems particularly bad, and the number of third-party efforts to replace it like Turn HA into ULTIMATE Data Analysis platform shows that other people are not happy with it either.
I might start pumping some effort into helping these efforts…