I seriously could care less what we as HN want out of a phone in a way. We are head strong enough to do something different for ourselves -- literally look at PinePhone, etc.
What I'm concerned about is the trickery that is sinister beyond belief, getting access that they never earned and do not deserve.
Here's an example: https://youtu.be/VrKW58MS12g?t=406
This 'hack' is quite insane... Brillant and horrid... and I foresee it happening left and right.
Seriously though, I have a hand typed letter from the mid 80's running a similar scam.
If anything, technology has made this sort of thing riskier for the scammers.
Consider how you'd reproduce the vigilante's setup using 1980's technology. It probably wouldn't be feasible.
You also can't retroactively undo a security hole: once you've installed malicious software the other software on the system by definition can't be trusted.
Malware has made it into Google Play store which is Google's fault. Same has happened to Apple (https://9to5mac.com/2021/05/07/emails-reveal-128-million-ios... https://us.norton.com/internetsecurity-emerging-threats-ios-...) so you cannot be guaranteed to be safe just because you are behind a walled garden, you still need to think for yourself.
Allowing app side-loading or different app store is not a security hole. Using non-approved apps or non-trusted app stores might allow for existing security hole to be exploited more easily but it might also allow for better protection against such security hole by providing better curated app stores for less tech-savvy users.
If you are arguing that some people will be tricked into installing malware from other sources then you are right that this change would allow that but it will still require user to go through few steps which should raise red flags for them. Some people just can't resist pushing that button without thinking and regardless of the consequences and in that case app store safety net is just temporary anyway, they are still exposed to the real world where that will harm them in a more serious way.