Some will get excited about the battery. The truth is Apple has TONS of data around battery usage. For the average user (read: +95%) the current battery is just fine for making it through the day. Yes, there will always be special use-cases but Apple designs for the average user.
It's like complaining that a high-end Mercedes does most everything but is missing a couple features. It fits the needs of most just fine and that's the point. There will never be a single product that covers everything every user could possibly want.
The iPhone 8 Plus performs slower in real world benchmarks and has a dimmer display compared to iPhone 7 Plus.
I doubt Apple would use these tricks unless battery life was a concern. Battery life is very important for a lot of people.