The maximum capacity of my iPhone 17 pro is still at 100% after 192 charges, that's after 1 year of usage. The extra battery life does reduce the amount of charges I have to do so that helps with the battery life.

I'm not sure where the capacity will end up after 5 years, but I think my iPhone 14 pro was at less than 95% at this point. Apple refused to replace just the battery on that one because of a small crack in the screen.