Yes, customizability is a trade-off, one which I am not willing to make :) For me personally it justifies the choice of a different product. I'm not only including launchers and icon packs in this, it's for example much easier to install e.g. an alternative YouTube frontend on an Android than on iOS, or to use an alternative app store (I'm assuming Android doesn't have anything like F-Droid or Obtainium, both of which I use to get free and mostly open-source Android apps). You could say that's a trade-off again, which it is, but I believe I should have the freedom to make that choice. It's not like I couldn't stay in the confines of Google's ecosystem and have a largely similar experience to a closed off Apple-like system, it's just that I don't want to. But perhaps I've strayed from customizability back into the openness territory with this argument.

If I understood your example about fine-grained and extensive customization, I think you've identified these possible challenges:

ease of access to needed settings
consistency of application

I think both of these can be solved by the manufacturer of the OS. Google has been streamlining their settings menu with every new version of Android and extensive developer guidelines about how to make 3rd party applications consistent with the rest of the system are now the standard. In other words, I believe ease of use and consistency don't have to be at odds with customizability, in fact they can reinforce and improve each other (example: setting a system-wide color tint that is then applied in all supported applications).

Slight tangent here, talking about consistency makes me think of another thing. I don't know how it is today, but when I last tried using an iPhone, there was no consistent way in apps to go "Back" from an activity. Most of them had a top-left arrow that took you back, but definitely not all, and the experience was all over the place. Sometimes you had to swipe right, sometimes press an arrow in the bottom left for some reason.. For all the talk about iOS's consistency, it was not a consistent experience at all, and I believe Android had it figured out much better (not to mention that having a Back button on the bottom makes much more sense, esp. with larger screens).

And lastly to the marketing point. Look, I know the reality of selling a product is paying a lot for marketing so that you can actually sell it. I understand that. I am just psychologically resistant to ads (I am less likely to buy something I see an ad for), and I hate giving into trends. I think it's part of my particular flavor of neurodivergence. And since having an iPhone is promoted as trendy and a status symbol or whatever, and seeing people give into that hype, that just makes me unlikely to ever buy one, and psychologically resistant to supporting these marketing practices with my money. Plus, the larger the corporation in general, the less likely it is to get a lot of my money if I have other choices.