A charged battery should be expected from a rental EV, totally. It’s not difficult for Hertz to install a fast charger at their locations to handle that for their vehicles and just cycle through the to keep their inventory charged.
Now 100% may not be realistic. Just like your phone getting from say 80% to a full charge can take as long or longer than from 0% to 80%. But a full charge isn’t necessary most of the time, and there are a lot of public chargers, even without the adapter to use 3rd party chargers on a Tesla for instance.