I seriously wish these kind of displays were more prevalent, not only for readability but for energy-saving.

I'd probably be willing to get a WearOS device if there was one with such a display and with a battery lifetime of more than two days. It's a reason why I stick to "dumb" smartwatches like the Pebble and Amazfit Bip, I don't really have to worry about battery life while still providing useful data.