I feel like comments like this always assume that it's a given that the average user having full control over their devices is a goal that the majority of people agree with and are interested in pursuing.
Unless it can be demonstrated that the lack of control over their smartphones is seriously, tangibly affecting their lives in ways that aren't just ideological, the public at large (and lawmakers by extension) are going to keep right on not really giving a shit if they have Linux-like package management or not.
If you're running a business, that is very much trivial. I just paid my bank $40 to send a wire transfer to a vendor. It costs $39.99 per month to be able to make apps for Amazon sellers. Out here in the real world stuff and services cost money.
... which means the amount of money spent is _not_ trivial. If you are not policing your costs, regardless of how "trivial," then how are you optimizing your profit? A "cost of doing business" is still a cost on your books. $100 is trivial for a larger business but if you're talking someone small or a side hustle, $100 is something that is not trivial.
Apple is literally in the top 10 largest companies in the world for several different measures. If they're achieving those numbers by giving the ole F'you to developers, that is a problem. Getting locked out of a distribution platform for 1~3 months, in today's world can cost thousands or even tens of thousands in sales even for small developers.
There are no other options for Apple. You can't install untrusted apps like you can on Android (which is still a huge pain and which no one does).
I almost feel like someone like the EU or California needs to mandate that both Apple and Google allow individual users to add 3rd party repositories in the same way you can on most Linux package managers. They can throw up a big warning about device security if they want, but unless there's regulations around it, there's no way for the average use to actually have control over his or her device.