Where are those people instead?

The vast majority of western society is in one of those settings most of the day

Planes also have charging ports

Trains have charging ports

If you are at the gym you can have a MagSafe portable charger in your gym bag that charges your phone when you hit the showers

Give me a few examples of who actually isn’t near a charger for 8 hours at a time

A full time skier or surfer?

I can’t think of the groups of people who need such long battery life

Most planes and trains in Asia don't have chargers. Maybe your country does. Your country is not the norm. Places that do have chargers are swarmed by people with tiny batteries desperately trying to charge up. And those charging spots charge about 1% every 15 minutes.

As someone who's been all around the world and goes places every week, I'd take a battery that lasts all day and charges when I sleep over needing to stop and try to get another 5% of charge wherever I can and constantly being on the lookout for chargers.

Also, people go into nature. We take hikes and walks in the park. It's nice to have a map there. It's also not easy to charge in the middle of the forest. And there are lots of people outside and needing good batteries. Nobody is staying home 90% of the time.

Plugging your phone in is annoying. I want to avoid doing that as much as possible by only doing it when I go to bed.

Aside from desiring a longer battery life, you'll likely be shocked to hear that some of us (non-iphone users) still use the Aux jack and the SD card slot too!