Basically every other comparable store charges the exact same 30% rate

Google, Steam, Xbox, PlayStation, Nintendo

The ones that don't just prove that charging a lower rate doesn't actually change the price the consumer pays in any way.

Google charges 15% <$1million

Steam charges 20-30% depending on how big you are, and probably has a sweatheart deal with EA.

Xbox and Playstation offer subsidised hardware and arguably have a 0% rate given that so many titles are published in-house.

Nintendo offers an effective 25% rate as 5% of spend is rebated to customers' wallets.

Microsoft charges 12%

Epic charges 12%

Are the different rates reflected in the prices on the store or does the customer pay the same price irrespective of the cut taken by the platform?

The different rates are reflected in the burnout, low pay, bankruptcy and failure - or the opposite - of the developers who launch on them.

Right now for example its basically impossible to make a reliable income just from PC, for the average solo developer or micro-studio, due to the insanely high 30% commission taken by Steam.

Its necessary to launch cross-platform onto consoles, and optimizing the graphics and control schemes for these devices means that PC is not the focus.

They should be forced to open up as well. The whole software platform business model needs to die.

Just because you don't like it, it should be forced to die? You know there are people happy with the way it is...

If I want an alternate store, it’s not to safe ~$20/year in commission, it’s to gain access to functionality to which Apple restricts access.

Why does Apple restrict access to certain functionality?

Because they don't like competition, for example.

I think it is about more than commission. Developers argue the rules can be applied capriciously and that many of the rules are paternalistic.

Yeah, that’s a much more legitimate issue than arguing about 15% vs 30% and where the line in the sand should be.

That still doesn't let me install (real) Firefox.

On the contrary, I would argue the exact converse. There are many reasons to want alternative app stores, and they might even be an effective market mechanism to avoid specifying some naive threshold like 15%.

Then money would be less of an issue, but we'd still be stuck with all the same arbitrary restrictions as today, like no third party browsers, no porn, political censorship in China...

Political censorship in China is just part of doing business there. I would like Apple to follow the laws where I live (which they do imperfectly, and they need to be held accountable), so I am not going to complain because they follow local laws in other countries.

In the other hand, their policy for apps with user-generated content is stupid, and their stance on adult content is pure ideology that belongs in the 19th century.

App is not necessity good, you can not impose price controls for apps like you can for food for example.

Do you really believe that setting profit margin for an industry is the government’s job? I am not libertarian, far from it, but this sounds excessive.