You can pay for Netflix right on the phone.

You can go to https://netflix.com

You can also buy an Android phone like 85% of the rest of the world.

Eh, I think this is one of the two points where the case against Apple's App Store model is the strongest. Not allowing applications to use third party in-app purchase systems is weakly defensible, but they not only don't allow that, they not only don't allow you to load an online store in a web view, they not only don't allow you to link to an online store that will open in Safari, the App Store terms literally do not allow you to mention the existence of other online stores.

There are arguments to be made -- and they're made in these comments -- that the App Store is a net benefit for consumers, but it is really, really hard to make the case that users somehow benefit from this.

Can I advertise in Walmart that they can buy the sane item cheaper from my own website?

I don't think that's a valid comparison in this case. You aren't advertising another place to buy the same item, you are telling people how to buy content for the item they obtained from Apple's App Store that is (a) necessary for the item to work meaningfully and (b) is not sold through Apple's App Store. Are you completely confident that if Walmart, for some reason, sold video game consoles but didn't sell the actual games for the console, they would maintain an iron-clad prohibition against telling their own customers where those games are available?

Can you show up at Costco and prevent them from selling your products at a lower price than you do on your official website?

Is Walmart the only store you're allowed to shop at?

Neither is the iPhone the only phone you are allowed to buy.

They allow Netflix to charge on the phone if they are willing to agree to the other conditions.