Not on the Xbox, which Epic doesn't seem to mind in regards to Fortnite etc.
Yes, but for many users this is a premium feature, not a flaw.
It is also difficult to see how it is a feature. In a world where additional app stores or side-loading was enabled for those that want it, it wouldn't somehow remove the ability to use a single app store for those that don't.
So, of iPhone buyers, you're left with two remaining groups:
1. People who care a little bit about side-loading but not enough to choose a difference device.
2. People who don't care about side-loading at all.
In any case:
> the people who really cared about side-loading
> 1. People who care a little bit about side-loading but not enough to choose a difference device.
This is not a useful model. If I choose feature X over feature Y, all you can really tell from that is that value(X) > value(Y). It doesn't tell you whether value(Y) <<< value(X). It's also important to note that this is vastly simplified, because there are many features and issues that people must combine and weigh against each other.
To illustrate, if a product offers side-loading but kills your mother on first use, if you choose a different product it doesn't mean you don't "really" care about side-loading. You might genuinely care a tremendous amount, but sacrificing your mother isn't an option for you.
I differentiate between products that I buy because they are a good option for me and products I buy because they are the least bad product for me. Phones are currently in the second group. It's not that I don't care about side-loading. It's that all issues combined, IOS is less bad for my purposes and preferences than Android.
To the extent that the lack of side-loading helps prevent the spread of malware and shady apps stealing user data, I think they value it indirectly.
Android has serious malware problems. Even Epic's attempt to distribute Fortnite off the Play Store has directly led to fake APKs being distributed to unsuspecting users.
I don't see how you can open up iOS to side-loading without exposing it to the exact same malware problems Android has.
The enabling of sideloading on Android phones already comes with warnings written in plain language, and even if you want to install an app from e.g. the browser it asks you to give the browser permission to install apps, so it's pretty idiot-proof...