Software isn't restricted, you can run software from anywhere, be it steam, a developer's website, your own software. How is Apple restricting you? With the iPhone you cannot side-load apps, but macos, you have the control. Where is there no choice?
ARM is not proprietary, its being used in more and more devices, from phones, to handheld game devices, to windows machines.
You can also run Linux on a Mac, there's Asahi Linux which runs natively.
As for ram, they're not the only ones integrating ram into the CPU and/or logic/mother board. Also When was the last time a consumer upgraded their ram? Yes, it was a thing in the 1990s, but even then the people who actually upgraded their ram was probably a small minority compared to those who bought the machines.
At the end of the day, we have options, choices, and alternatives, in software, hardware, and operating systems.