I have a delivery job where my route is done through an app. I use navigation to get there, scan packages, take pictures as proof of delivery, etc. I work 7-10 hours per day. If I don't plug my phone in every time I get in the car, my battery will be dead in a few hours. Sometimes when I'm doing a tight route where I'm getting out every 2-3 minutes I don't plug in every time and after an hour I'm down to 65%. It goes down faster below 50% than it does above 50% so I keep it as charged as possible. Camera especially eats up the battery. App developers aren't the smartest at battery usage. I sometimes get updates to the app that will literally eat battery so much that I can watch the battery go down 1% per second if I don't keep it plugged in, and then it just holds steady instead of going up. I have to turn the screen off and listen to directions instead of looking at the map, and then scan the package in my car and take the photo on zoom from my window. Luckily they usually fix that shit fairly quickly when the complaints come in. Can't do my job without it. I've had a cord break and not notice it's not charging for a while, and suddenly it's below 15% and I'm scrounging for a cord because I know my phone will be dead in like 20 minutes. Or someone who uses their phone as part of their job.