You are right. Plus often my battery is still well charged from the day before. Like I said something I would do in the city but then I would not buy a Prius
I've seen the new packs. Still have my 18 year old one doing ok plus a spare but once my doors and roof are changed or it breaks something I might consider. One reason I would not add batteries
Also there was this
In 2015 BASF produced a modified microstructure that helped make NiMH batteries more durable, in turn allowing changes to the cell design that saved considerable weight, allowing the specific energy to reach 140 watt-hours per kilogram
https://sustainableskies.org/basf-nimh-battery-rebirth/
Haven't seen one around yet though..