Earlier quoted context omitted.
I had a lot of experience with tons of devices from both ecosystems (because I was at least part-time in mobile dev) from about 2011-2019 and a consistent hallmark of Android devices—regardless of manufacturer, Google's own devices weren't much better—was that their battery life, and especially idle battery life, was markedly worse than iOS devices. In fact, I came into that world as an Android user, and gaining exte…
It had to have been the apps that were running on Android. It's nothing to do with the hardware. I used to have my pixels, back from 2012, regularly at less than 10%, and would still last overnight as you describe. If a pixel not running any crap apps was worse, it was only be a negligible amount. The gap was never that big, it was more the software that was running than any hardware issues.
No, it really was. I wasn't hallucinating stock Android tablets dying over long weekends while iOS tablets would still be usable for testing without needing to plug in, after three weeks in a drawer. Or the phones needing a daily charge if you barely used them, while Apple phones could go 3-4 days under light use. There were no exceptions to this in Android land.
[EDIT] Incidentally, yes, I agree it was largely a software issue—but at the OS level.