Where do we leave those who have to live with their devices, or simply lacked the knowledge to make that important distinction at the time, or things have changed and now they need to install apps that have not been approved by Apple. Wouldn't the solution be to offer people that need to live with their right to sideload apps on their devices an escape hatch, instead of telling them to change platforms?
Its equally correct to say, "the rights of those people are needfully restricted."
If people cannot choose their devices, or are miss-informed that is a big issue and should not be tolerated. Meanwhile, allowing Apple to build an amazing, curated customer experience for me is why I choose Apple's ecosystem for me and my family. I don't want my parents or future children getting misled into downloading malware, or berated by ads, or giving out their credit cards to an un-trusted application disguised as "verified by Apple".
The walled garden is a feature, with tradeoffs. Not different from my shower head or fridge making feature based tradeoffs. If you don't like the energy bills for your washing machine, suing or regulating the company to improve it isn't the right strategy. Just buy a different brand that matches your needs.
If you want sideloading on iOS (beyond what the web offers), buy an Android.
What about the users who lacked the important knowledge that the apps they downloaded had deceptive advertising, or malware?
Should we no longer be able to run software that has not received third-party approval?
If they did thirty seconds of research in the market they would see that there is a large ecosystem of devices that allow unsigned apps to be installed by the owner that they could have chosen.