Earlier quoted context omitted.
People love to hate on Apple but the fact is, they continue to release features to better showcase or restrict developers that abuse your privacy. The "walled garden" also ensures they apply a ton of checks to apps to better restrict abuses. Sometimes it's overly sensitive and bad things happen, but in general it's awesome that over time it becomes harder and harder to get away with apps blatantly spying on you.
The walled garden does no such thing. Either iOS is secure or it's not. if it's secure there is no need for the walled garden. Let me run anything and trust its security. If it's not secure then the walled garden is security theater because it's trivial for any app to hide its true intent.
So let’s define our terms a little bit. What is our walled garden and what does it bring to the table in terms of security?
Off the top of my head I’m thinking we get more eyes during the review process, maybe some static/malware analysis, etc.. Another thing is the “soft controls”, not allowing certain classes of apps that Apple doesn’t feel “belong” in their garden. Well that’s a net security benefit too. Less apps, less possibility of exposure, more careful and selective choosing of apps allowed, you’re going to see less shady stuff and abuse.
Compare the two app stores, it’s not even close.
So the security benefits of a tight review/control process are pretty clear, and play out in the results of malware outbreaks between Google and Apples app stores.
The question of trading freedom for security is another topic, one that cuts deep into the fabric of western society. Too deep for this convo!