I think you make a good case for yet another Feature Request regarding Recorder. It would be great to have some sort of filtering on what gets recorded.
Maybe it could include the ability to limit the number of changes over some time period. Or a range within which values are to be recorded (or not.) Or maybe the amount a value needs to change before being recorded. I have temperature sensors which report in tenths of a degree. Maybe only recording whole degree changes would be sufficient (and save writes to the database.)
Creating templates for each entity, just to work around the limitations of Recorder, is less than ideal. There are other Recorder FRs like this and this. With all the other great things the HA dev team is doing, it would be nice to see Recorder get some love.