Owning my computer is still relatively possible. I can build a computer from parts which I can choose, and have a choice in which operating system to install on them. Laptops are slightly more closed, but even on those I can choose the OS myself.
Modern smartphones however, seem like walled gardens in which I have no control at all. I cannot choose any of the parts, and even doing simple reparation tasks like replacing a battery is a nightmare these days. I am locked into a single OS on my smartphone, which either spies on you or is locked down even more. Every iteration a bit more control is taken away from the user. And its increasingly hard to step away from them, since a lot of normal interactions such as banking almost requires you to have such a phone.
Both Android and iOS suck. I've made my own Android phone tolerable with F-Droid and trying to ungoogle it as much as possible. But unfortunately I find myself locked into using google play services since solutions like MicroG just don't cut it. They lock me out of slightly too much of my daily smartphone usage (note that this is definitely not the MicroG's developers fault, they have done amazing work).