This is such a tired argument. Nobody is arguing that iPhones should be rooted by default, only that they should be rootable.
I like the fact that Facebook can't pull their apps from the store, put them on a rival store with lax standards, or otherwise circumvent the app store controls. These controls clear benefits for me, but side loading and alternate stores would cripple their effectiveness. In fact crippling the effectiveness of these controls is the purpose of side loading and alternate stores.
If you want a phone you can root, buy one. There are options out there. Why do you want to take my choice away from me?
You keep repeating this disingenuous argument. If you don't want to root your phone, don't root it. If you don't want your kids to be able to root their phones, don't pretend like you aren't taking away their choice.
If you don't want rival stores with lax standards, don't install them. Just don't keep telling people who want to be given a choice that they're somehow "taking your choice away from you".
If you want to be in prison, go ahead, but don't pretend that having the option to leave is somehow "taking your choice away".
If it were possible to root an iPhone, Facebook would have never agreed to give users the option to stop tracking them across apps; they would have instead said “please watch this video and do what it says to continue using Facebook/Instagram!” and guide naive users into rooting their phones.
Closed ecosystems have many advantages (and disadvantages) over open ones. However, a closed ecosystem with a gaping hole in the wall is no longer a closed ecosystem; you can’t have it both ways.
This doesn't happen on Android because Google has no interest in enforcing strict privacy policies on the Play Store.