How are you getting 3 days of usage out of an iPhone? I don't use my iPhone X much at all (mostly texting and occasional web browsing), but I'd be lucky if I could get 2 days out of it. Meanwhile, my last Android phone would consistently last 3+ days on a single charge.

(To be fair, I ran LineageOS without Google Play Services installed, which makes a huge difference, so it's not exactly apples to apples.)