I have both iPhone X and Pixel phones. Up until the iPhone X, Windows Phone was my daily driver - I loved the OS; may it RIP. I am not much into customization or tinkering, so to me it is just a phone with several apps, music and photos. So, the iPhone is my daily driver even though I use all the ecosystems Apple, Microsoft and Google and they all have their good and bad traits. I miss the tile's from Windows Phone as it was so easy to organize your home screen. Apple and Android, I really dislike that you have to flip through multiple pages; even in Windows Phone you could do a quick search by first letter of apps to narrow the list.
In regards to privacy, I prefer Apple. I've always thought of Google as the Devil regarding privacy. Google is merely utilizing their OS to gain marketing information to sell. Each app request permissions to various levels or personal information and their seems to be more spyware apps in the Play Store. Google is nothing more than a marketing analytics company.
Segmentation in the OS. I think we can agree that not every Android phone runs the most current version of Android. Leaving the haves and have nots. Carrier phones are loaded with tons of bloatware and most times are several versions of Android behind when released with no plans to update them. Apple does a much better job of ensuring their products receive regular updates, regardless of carrier.
Device Options: Hands down, Android wins. I prefer pure android, I how ever MFG or Carrier can implement it how they choose leading to confusion in the user base. They should use the KISS method for out of box experience and if you want to customize go ahead.
Reliability, my pixel reboots several times a day, for no reason. I have like two apps loaded on it. My iPhone just works.
While both aren't perfect, I lean to IOS for it's simplicity, respect for my privacy, ecosystem integration, OS standards and reliability.