Thanks, your position certainly makes sense to me regarding a Pixel phone with the stock software on it, but much less so when considering options like GrapheneOS or any of the Androids made by other non-Google companies (like OnePlus, etc). That's the point at which usually "user experience" or "I'm already in the Apple ecosystem" usually come to fore-front as the reason.

I don't really trust of those big companies, which is where GrapheneOS really shines. Open source, lots of enhanced privacy controls, but also as much of the Google ecosystem as the user wants. If you maximally distrust everyone, you can roll with pure FOSS. If you're somewhere in the middle like most people, you can pick and choose the pieces that are worth it to you (Google's Pixel Camera app is a common one for example). Graphene OS is also trivial to install now thanks to the web installer, so pretty much anybody who can load a web page, plug in a USB cable, and follow the explicit instructions to unlock the bootloader (which is stuff like, "open settings" -> "click about", etc) can do it.