It feels like we have regressed a lot from where we were in the "golden age of the desktop". I mean, we actually had standards for things - remember CUA? And UX was designed in a way that made it so that once you learn a few basic tricks (like double click and drag and drop), they would work everywhere, and they would do so consistently. Consistency, in general, was key to the UX of that era. Some things might not have been as easy to access as they are today, but all things could be found where you expected them. Even the menu hierarchy was largely standardized.
Now, even if you stick to one particular platform, it often changes the concepts radically within 4-5 years; and many of those aren't even consistently applied. Worse yet, instead of fixing the mess, the UX designers just keep piling more and more stuff, like Apple's "3D touch".
To take your 3D touch example. I'll bet it went a little something like this; development said 'we can now detect pressure', leads (inc UX) brainstormed on ways to utilise the functionality. Then it's soley on UX to make it usable.
I've never been involved in a situation where I get to demand capabilities that hitherto did not exist. Nor have I ever held the power to stop-ship. We have varying degrees of touch on functionality as it evolves for sure but not the power you assume we have.
We don't live in a reality where any company, Apple specifically, says 'hey customers, we realised we actually got things right on the last release, please give us more money 'cos shareholders'
If everything was evaluated by cybersecurity and UX experts first, we wouldn’t have half the problems, but people aren’t interested in those sorts of issues, it is more of a matter of getting there “firstest with the mostest”.
That's an extremely brash assumption. The reason privacy and security haven't been built into the core of everything we do is because the ease of use within highly secure systems is inversely proportional to it's UX. The more secure you want something to be, the harder it is to learn and use.
I think the issue is that Apple keeps adding functionality to iOS, but seldom removes functionality. So all these "non-essential" features end up relegated to harder to discover actions.
That means that the fact that phone screens have gotten larger is irrelevant because whatever complications or features are added have to work broadly and consistently amongst devices of varying screen sizes. Web developers actually have it down best when it comes to responsive design but even responsive design makes for a different experience on mobile vs. desktop and I think Apple is trying to avoid that. An iPhone might be "hard to use" for someone that's not tech savvy but, once they learn how to use it, they now have an easier time across Apple's entire product line, not just that one device.