These “analogies” are disingenuous. I take it you’ve never jailbroken your phone, so you’re not aware of the possibilities of customizing the springboard. Many of the UI enhancements that Apple has added to the springboard over the years actually were inspired by jailbreak tweaks. Speaking of jail breaking, the iPhone ecosystem isn’t any less secure, even with the existence of the Cydia App Store…
Adding alternative app stores to the iPhone is NOT akin to walmart adding Target checkout machines, it is simply giving users the ability to get Apps from alternative locations, just like Apple users can on the Mac. The iPhone OS is based on the macOS kernel, and if macOS is safe enough to tolerate side loading, why is iPhone OS, that is based on macOS, not? It’s all about profit, alternative app stores would negatively affect Apple’s profits, that is the long and short of it.
No, those analogies are accurate.
Second, just because something CAN be done doesn't mean it SHOULD be done. I am fully aware of the possibility to customize the springboard. I'm also fully aware Apple could release an entirely different OS for the iPhone. Or it could allow a third party to do so. Just because something is technically possible doesn't mean it should be forced on someone/some company OR that its a good idea. As an example I'm sure you would be opposed if your bank decided to transfer all your money into my accounts. It is after all a possibility and something that CAN be done.
And actually yes, the existence of the Cydia App Store did compromise the security of the devices it was installed on, just as Jailbreaking compromised the security. By its very nature thats what Jailbreaking is, compromising the security.
Finally, regarding your straw man argument about the macOS kernel, no one has ever argued its not technically possible for iOS to operate the way macOS does in regards to app distribution, so I'm not sure why people like you continuously bring it up. This isn't an argument about what's technically possible, its about Apple being forced to change its platform to suit the needs of a bunch of selfish whiners. That Apple doesn't take the same approach on MacOS is dictated by two things, one, the long history of MacOS being a more open operating system anyway, and two, Apple treating its Mac line and its iDevice line as different types of devices with different capabilities and different tradeoffs. Could Apple add side loading to iOS just like macOS? Of course, no one is debating that. They could also add touch support to macOS. Its not a question of can, its a question of want.
Apple doesn't WANT to make iOS an open platform, and, as long as it is upfront about that (it is) AND it is not a monopoly (it isn't) it should be allowed to. People should have the following options:
1. Buy an Android devices and get side loading like they claim they want
2. Buy an iPhone and deal with living without side loading
3. Complain about it
4. Try and convince Apple to change their mind
What they should NOT get to do is FORCE Apple to change its model, robbing those of us who prefer the Apple approach from the choice between two different phone platforms, and flattening it into one style. The ones who are against choice are people like yourself who want to compel a company and its users to give you everything you want. You are free and always have been to choose a device that has, from the beginning allowed side loading and alternate app stores. If you don't like Android despite that, well tough luck, you can't always get what you want and again you shouldn't be allowed to force someone else to give it to you just because you selfishly demand it.