Users don’t care about if the platform is “open” or if they can install Linux. In fact, in many cases, the things are a massive source of pain to end users that want devices that just work, which the iPhone and iPad largely do.
It’s also, by the way, never been easier to build your own hardware from ready-made components and platforms.
I don’t know why we should lament users choosing devices that are easy, fun and reliable to use, and that provide them with single tap access to massive software libraries and entice them to pay for that software. Seems like an absolute win to me.