Agreed, and it goes even beyond health. My 5s on iOS 8 was quite abhorrent. Push it a little on LTE, and battery life scraped 3 hours. I'm not even talking about heavy camera usage. Maybe outdoor brightness (60-70%), some web browsing and texting, light use. It was bad ever since it was new, and it had neither a degraded battery nor was it even updated. It was just poor by itself. We've come a long way since that, like you said. My Xʀ on iOS 12 lasts probably 4 times that with the same usage, let alone a 13 Pro Max on iOS 15.People also seem to forget that phones of old had HORRIBLE battery life, fairly quickly too.
I rooted my Samsung Note 3 and had several apps that would monitor battery health. After 6 months my OEM battery was at 50% health. Not 80%, 50% something. Now sure, I went on Amazon and bought a $17 Anker battery to put in its place but still, even that battery didn't last very long either. My HTC My Touch and Droid 1 weren't all that great.
Devices have come a long way and batteries today are a dream compared to what we had. lol. (My opinion).