Why can't I have an UI-configured state_class total History Stats sensor?

Configuration
1

I’ve created a sensor to track the daily grill use here at home. This sensor resets every day at midnight.

According to the documentation

This sensor should be of class total because it resets down to zero. I only get options for measurement and total_increasing.

Why??

Also, how can I create a sensor that only ever increases, and never goes to zero?

2

FYI I ended up using the MeasureIt integration, which allows me to define both a daily and a perpetual stats sensor based on a single template, with what appears to be the correct sensor class.