Already happened.
1. Headphone Jack
2. Still no USB-C
3. Notch on iPhone X
4. Price on iPhone X killed it. ($1500 once all set and done).
5. iOS locked down O/S with less features than the competition.
I've moved on to a Note 8 now and don't regret it. Although my whole family still has iPhones, I'm the only stray right now.
The first 3 on this list doesn’t really bother me but the 4th and 5th seem to annoy me a bit. That and the fact that the 8+ doesn’t seem like much of an upgrade even though coming from the 6s it is. In hindsight I’d rather have gotten the 7+ a while back with the 128gb of storage and waited to see what Next year would bring.
Side note: Is the X going to really be that scarce?
Since April I have wanted to jump ship to the s8/s8+. I decided to wait it out to see what apple was offering. Of course, like last year, apple slightly disappointed me with not only the lack of design change for the 8/8+ but also the price of the X.
I am torn. I have a 6+ now and it has served me well and continues to do so, but I long for a better camera. I opted out of the 7/7+ upgrade last year because of the back order and the fact that the design didn't do it for me (in hindsight would have gotten the 7+ and held onto that until 2018). Plus having better internals doesn't hurt.
I am also kind of bored of iOS, but it works an works well. iMessage is a plus with my family all having it, plus answering texts on a mac. I however have been migrating towards google services so a transition to android would't be as tough.
So, with that said: Need a better camera: 8/8+ s8/s8+ and X offer that. Design: s8/s8+ and X offer that (samsung sightly better). integration: iOS wins, but google services will help ease the pain if I go android.
Wildcard: get the s8/s8+, after several months if it isn't for me, sell it, cut losses, go back to iOS with most likely the x.
I agree with your statements. Although I don’t use iMessage.
To be honest I don’t use any of the Apple features much (and I plan on keeping my iPad). I simply like Apple for the ease of use on their device and being able to plug in and have my device mirror my last device.
I use FaceTime occasionally but I can still access that via my iPad so not a total loss there.

IMessage I don’t use, don’t use iCloud either. Don’t use my Apple TV and I cross sync anything across multiple platforms. That’s the reason I’m thinking a Samsung device might be the way to go.
Can’t find too much wrong with Apple outside of the fact is they seem to be a bit behind in certain areas of tech/design.
This whole 8+ and X and iOS 11 is what is prompting me to switch.
I’m holding back due to partially wanting to see the x and my 6s is still ticking, not mention I got the aw Stainless series 2 less than a year ago.
However with all that said if I can mirror most of my alerts on Samsung like I can on my 6s, get a bigger better screen, more apps for free, more features, a watch that looks like a real watch... the that might be the way to go. I’d also admit I’d miss this system and setup here but, it’s just missing something for me.
I’m not big on the s8+ only coming in with 64gb of memory but I’m also not big on Apple not having a mid tier, and I still have about 25-30gb free so I think I can work with a 64 still. Only other reason I’m not rushing to a Samsung is I’m not the biggest fan of the curved screen. Wish it was all flat but I’m leaning towards it so we’ll see what happens.
I will finalize my thoughts with this, I’m a creature of habit and once I switch eco systems I not big on getting everything setting back out and running again on a new platform hence this is why this is my 2nd iPhone in a row. I’ve had Apple for 3 1/2 years and had a 4s before that when I briefly switched to Samsung and dropped it because of that lag which if I experience that again I’ll be using an iPhone for the foreseeable future.