They obviously wouldn’t be allowed to make it so difficult that nobody could be persuaded to do it, which defeats your point.
https://arstechnica.com/gadgets/2019/10/the-internets-horrif...
Here is the exact problem we are talking about, happening today on Android.
The mechanisms you are talking about have been proven not to work.
As for laptops - they are. It’s not ‘stupidity’ that causes most people not to understand these risks. It is a lack of time to develop the expertise. Many people would like to pay Apple to manage these risks for them. For those who do not, there is Android.
You are still avoiding to answer why is Apple not locking down the MacBooks ? I mean is for the users safety, are this users in danger and Apple not caring enough abut them?
The answer is simple, you can make it safe by default and let the user unlock their device(from BIOS or from a setting s) Apple can afford to hire a UX designer to make the warnings clear for average person, can afford a lawyer to put some disclaimers there, can afford some developer to implement this unlocks. The reason they do not do this is not for your safety is for money and when they will be forced to implement it I am sure you will praise them on how a nice job they did when implementing it.
You are proposing to have the government start mandating software features, which is absurd given your claim not to want the government controlling your phone.
I already answered your question about your MacBook but you chose to ignore it. The answer is that they are locking down the MacBook to protect users.
As for the ‘hire a UI designer’ argument. That has been proven not to work, but again you are pretending not to see this.
If you don’t think Facebook or Google could persuade people to install a store, you are out of contact with reality.
Once installed, those stores would be just as compromised as Google and Facebook have already proven themselves to be over and over again.