The problem is Apple have tried to shoehorn in so many features and extras that it has become necessarily complex.
The problem is that Apple started off with a very basic concept; This is a phone, and each app is a self-contained silo.
A decade later, that paradigm doesn't hold up, but in order to fix it, now, with millions of legacy apps, would require the type of effort that Microsoft puts into making Windows backwards compatible, and Apple just isn't like that.
It's funny, I completely agree with the OP, but for completely different reasons.
A decade ago or whatever, I was happily using Windows Phone 7. Facebook and Twitter were integrated directly into the phone, and the photos app had a stream of images pulled from Facebook, Twitter, the camera roll, and probably any app that would choose to plug into the framework. It was a cohesive, integrated experience. Asking Cortana for directions to the nearest Starbucks just worked, and would bring up the maps app with directions pre-populated. It was, in short, really cool.
But Windows Phone disappeared, and I had to move on. I picked up an iPhone, and while I didn't particularly like the silos that are each app, there were apps, and I was happy enough.
But that was 6 or 7 years ago. Since then iOS has added features, like Siri became usable,
live tiles widgets were added to the home screen, as well as an all apps list, and the UX got a facelift. But it's still the same underlying OS as it was a decade ago, and quite frankly it's boring. Which wouldn't be a problem if it worked, but it doesn't. It has a random bug here or there, and I'm not happy with it. I don't love it. In some cases, I actively dislike it.
So many decisions just scream "We won't do this because we want you to buy another Apple product" and it's getting old. Why can't I determine the battery life of my headphones on my mac? I guess if I have airpods it doesn't matter. And I can't keep the time on my lock screen, but if I have an Apple Watch it doesn't matter. etc., etc., etc.
Apple holds its users in contempt, and the only reason they have the market share they do is because there's nowhere else to go.