in my experience iPhones take ~90 minutes to fully charge, but similarly to your experience they charge up to the first 50% much faster with a faster charger, though more like 30 minutes instead of 5-10. (I'm jealous!)

And you're right that it seems like they have smaller batteries! Like my non-large iPhone 14 pro has a 12.38Wh battery but it lasts all day easily. Never thought about it before but this must mean that Apple's chips/software just pull less energy. (also I was wrong before, if a 12.38Wh battery takes 90 minutes to fully charge then it's average charging rate is only 8W, even lower than the 10W-12W I guessed!)