Yeah, all day battery is a HUGE deal in situations like that.
When I was in Italy for 30+ jam packed days 2 years ago, I did everything on my phone. I mean it worked hard all day long. Navigation while walking (lots of on screen time there), web lookups, translation duties with text to speech/speech to text/via camera reading signs and menus and I took literally hundreds of pictures every day. Thankfully my device took everything I could throw at it and lasted all day every day. Only 3 times I had to go to the battery bank and 2 of those just to be safe, only once was it mandatory. Each time that was a disappointing PITA. Overall though, my phone performed like a champ in the battery department and anything else would have been unacceptable.
For some things battery endurance is all that will do.