You sound like pretty much my exact situation and why I'm wanting to jump back to Android. I've flip flopped a ton over the last 4-5 years. Currently using a 6s Plus and have been doing so since December of last year.
You definitely hit the nail right on the head for me. While I love a lot of the things that Apple does, and does so well, it's the things it's lacking that are really starting to stand out. Default apps I 110% agree with. Why, for the love of all things holy, can I not set Google Maps and Chrome as defaults? I hate Safari. I'm not going to use it. I use Chrome because it syncs to everything I use. My two Windows laptops, my phone, my Chromebook, etc. And I don't care what anyone says, Google Maps is superior to Apple Maps, which doesn't suck anymore, but it isn't Google Maps. I also miss that I can't just glance at my phone and see notifications. I have to swipe to see if there's anything I need to tend to. Just seems like extra work for nothing, because Apple says so. I also use Google Photos, and it won't sync in the background unless I have recently opened the app. I also feel like my homescreens can work for me in Android, rather than just having a sea of apps and folders. I also despise the way that 3rd party keyboards work in iOS. No swipe in the Apple keyboard and the great third party keyboards like SwiftKey and GBoard don't have the dictation microphone, as that's only allowed in the stock Apple keyboard. I also hate how randomly the third party keyboard just disappears and defaults to the Apple keyboard.
The freedom with Android is nice. I'm really missing it after 8 months with iOS again.