Right, but my point isn't that "we all need to use only Free Software" (even though I think it would be great if we did), but rather that these companies, let's take Apple for example, consist of engineers like ourselves. Why are we not fighting harder internally that these products & platforms should be less restrictive? There's a myriad of arguments about "security" and whatever else that can be made, but even something like in the case of Apple with macOS just having a checkbox that lets you run unsigned code and if you select that then you acknowledge the risks would go a long way in my book. It's similar to how Pixel devices work. There's a barrier to unlocking the bootloader that requires the user to acknowledge what they're doing, but it is possible. It doesn't need to be everyone using Free Software, but we should at the very least be far more insistent that these companies give us the option to use our devices as if they are truly our devices.

Any engineer I've met knows Apple's "security argument" about the App Store and Sandboxing/Isolation are two completely separate things, the problem is most non-technical people believe Apple when they say the App Store keeps them secure.

At this point I don't think it's realistic to expect engineers to solve this problem —Apple would retaliate by booting them from the App Store of burying app reviews in red tape. What's probably needed is legislation that mandates hardware manufactures can't restrict what users are allowed to run on their devices.