Yes. But this is trivializing the definition of monopoly I just warned against.

What can't be construed with this logic?

Verizon holds a monopoly on the devices they allow on the Verizon network. Wal-Mart holds a monopoly on the products they allow on their retail floor space. Xbox holds a monopoly on their game compatibility. McDonalds holds a monopoly on selling burgers inside McDonalds. You can define these trivial "micromonopolies" on literally everything you want. Which is why courts have never punished any company for this nonsense line of reasoning, especially when it's on a company that holds no actual "macromonopoly", and monopolies by virtue of existing aren't illegal anyways.

Phones are the way of interacting with much of the world, unlike xbox or McDonalds. People consume their news using them, pay their bills, make photos of their kids, communicate with their family. It's a completely different realm.

There are two oligopolies on the market - Google (via google play) and Apple (via apple store), both are affected by the law.

Sure, and by existing laws and court rulings they haven't done anything wrong except be a preferred choice by many consumers. This is not comparable in any way to antitrust transgressions that got Microsoft in trouble, nor do they have the market share to manipulate that's comparable to what Windows or Google have had.

FWIW, I also want a more open iOS platform, but I don't think you can demonstrate that they run afoul of any existing antitrust laws or prior precedents either and trying to redefine what a monopoly means, exclusively to to the iPhone, is never going to work.

Not anymore than Honda or Ford hold a monopoly on their cars…

But after I bought a Honda or Ford I can do with it what I want and install whatever aftermarket stuff I want. Ford makes no pretence to have an exhaustive whitelist what I can do with my car, whereas Apple does.

(In recent years some of the electronics might be locked down, or I wouldn't be surprised if they are, but this is also criticized and the reason things like right-to-repair laws have been proposed and in some cases enacted.)

I mean didn't we already rule that as true? That's why there are so many laws forcing the manufacturers to produce and sell parts for N year, allow third party repairs shops, etc.

Like of all things to pick cars are literally a place this has played out where Apple would be in the wrong.

the monopoly car companies have on their cars is one of the ways they fleece consumers. It's why they have pricing power on repairs, can charge whatever they want for their self driving solutions etc. There's a reason why almost all of them are trying to turn their cars from mechanical vehicles into glorified software/service platforms, it's a way to lock people in.

In a world where hardware and software is open and interoperable and you can say, buy a self driving solution from any vendor (which is essentially what comma does in a hacky way), consumers benefit. Same is true for phones or laptops.

Fine then apply rules equally, I want to be able to use Nissan parts in my BMW and play Xbox and Steam games on my PlayStation…

There are advantages to having a walled garden and I would want to have some assurance that I would be able to block side loading and that it would never be applied without it being clearly and constantly visible to the user. I also want to be sure that no 3rd party can compel me to install their own App Store to get their app which is a quite possible and likely scenario due to the DMA.