WTH: Why can't you make template sensors from inside the UI

It would be very nice to be able to make a template sensor (let’s say under helpers).
I’m using a couple of sensors that I now have to add in my configuration file. It would be way better to build and test them in the UI and be able to directly use them.

Examples:

  • Loadbalance sensor that displays the balance between my solar production and my usage (injection - consumption)
  • Sensor that displays my current savings on self used solar energy (total solar production - (injection tarif1 + injection tarif2)*price/kwh)
    -…

already a wth