Force-closing apps and user habits

You probably already know it's a myth that force closing apps (sliding it up all the way out of view so it disappears from recently used apps) on iPhone saves battery. In fact it drains the battery faster, because it interrupts the OS's algorithms for holding app data in memory for fast retrieval. Essentially, it costs more electricity to retrieve data from disk than it does to keep it in memory. By force closing it, you kick it out of memory, which forces the OS to load the whole thing from disk next time you open it.

Right, so given this, why hasn't Apple done something about it? Surely they will know by now that this is a widespread user behavior. They could add a prompt: do you really want to close this app and waste battery?

Well, they could, but that might come across as patronizing to some users. Maybe they made the call that the battery drain is only marginal and lets the user feel in control over their device. Yes, they might have to charge their phone a few minutes earlier, but that doesn't even compare with the impact of screen brightness or heavy background location fetching.

It's a great example of where technical reality doesn't align with user psychology.