Apple creates a walled garden, where they decide what you can and cannot run on "your" device. Even if such devices are useful in specific circumstances, the problem of freedom is still there.
If the phone owner is not knowledgeable about the dangers, they should not be required to become a security expert and download special apps in order to deserve protection from those who would install privacy invading apps on their devices.
Now, it seems you are trying to argue that not computer literate people need a single chef (Apple) to tell them what to do and what not to do with their devices. Let me explain to you that freedom, which Apple devices lack, would allow such people to choose, whom they trust, increasing the competition and improving the market situation. For example, you go to a repair shop you trust and ask them to install any operating system they think is reasonable. It also concerns physical repairs. Apple more and more prohibits independent repairs.
Even if Apple is solving "big problems" as you claim, the answer given is still legit. There are people who need freedom and Apple goes against it in many ways. And it is not always possible to switch to other vendors, see "Vendor lock-in" in Wikipedia.
tl;dr: You do not have to be computer literate person to benefit from such freedom.
Search the article for these words: roommate. boyfriend. partner. family. household. abuse. abusive. stalking. stalker. spying.
No hits.
The article is 100% free of any mention of one of the top dangers Apple addresses for users with its built in protections. No phone can fix the problem completely, but iOS bends over backwards to ensure that a user who takes an active interest in protecting their own privacy has the tools to do so.