There's secure by default, and then there's stuff users can't override even with great effort. Android restricts some dangerous operations by default and makes users jump through a couple hoops to acknowledge the risk. iOS usually forbids them entirely.
The ability to build better things is the reason why you can now sit here, using technologies built on that "shit show" machine, and bloviate how new generations aren't allowed to build new things anymore because a megacorp needs to feed its greed.
In any case we are largely still learning when it comes to security and I don’t really want to make things less secure for the many just to satisfy the few.
The upshot of this is that Apple can unfairly compete in all sorts of verticals just by owning that platform. A lot of companies could make a good Airpod competitor, but without access to the same functions as Apple's they're hamstrung. Watches have this problem even worse.
Say what you want about Microsoft at their zenith, you COULD compete with their browser, in fact, people did. You just can't with iOS. That's more important than some users having poor security. (And really, how are we going to worry about phone security when there's a system as stupid as passwordless social security numbers being the key to your financial life?)
The natural duopoly needs to be regulated such that it doesn't spill over into every tangential market.
I do not in fact see that. PCs work pretty damn well, security-wise, even with clueless users. I'll grant you it isn't as secure as phones, but it's by no means horrible.
I actually disagree with you that things are good, security-wise, today.. They are still pretty bad.
Back then was extremely bad.. Back then, Windows was never designed to be a networked operating system and was just full of security problems like you wouldn't believe.
Phones, for better or worse, contain much more private and personal information about users than their computer I would bet on average.
So I understand the urge to make phones more secure by default and to help users avoid foot guns, even if it means restricting their choices.
You are likely not the average user, and I think it's a bit selfish to demand total freedom, that you can manage safely, when for most users they would be worse off.
In a perfect world we wouldn't need this but we certainly don't have one of those.