Different phone users have very different usage patterns, in my experience.

I don't use my smartphone at home (I have a PC), at work (I have a PC, and a sense of professionalism), in between (can't use a phone while driving or cycling), while exercising or while socialising (it'd defeat the purpose). I'm basically checking public transit schedules, calling taxis, making payments, and occasionally taking a photo or sending a message.

My phone's still at 80% when I put it to charge while I sleep.

On the other hand, a person who spends a load of time on public transit, streaming netflix the whole time? A person who listens to music all day while they work? A delivery/uber driver? A teenager without a computer of their own, who uses their phone for games and social media? And maybe they're on a budget so they have an older device and/or a smaller battery?

These folks are cycling their battery twice a day. Buying portable power banks. Getting fast chargers, for an early evening battery top-up.

It's these people who need to replace their batteries.