> 1) Many App Store apps are completely free, paying nothing to Apple except the $99 per year fee, so they have no stake in this issue.
I don't see that as a problem.
> 2) My understanding is that more than 90% of developers in the App Store make less than $1 million per year and thus are covered by the Small Business Program, which charges only 15% rather than 30%. Revenue in the App Store is extremely top-heavy, with most going to a relatively small number of the top developers (such as Epic, previously). How much are developers willing to risk just to lower the 15% cut somewhat?
I can't answer that question for any particular developer. But if my PSP charged me 15% I'd be looking for another one and if my PSP arranged for things in such a way that I'd owe them anyway by virtue of developing for a particular piece of hardware that they already sold and made their profits on I'd go and do something else with my time. Which is why pianojacq.com is on the web and free instead of an App in the App store because that way Apple/Google don't get to increase their grip on the market regardless of whether or not it is free. I disagree with their business model to the point that I'm not partaking in it at all.
> 3) Let's be clear, you're talking about a strike. Many developers derive their entire income from the App Store, so withdrawing their apps means no income. A wealthy corporation such as Epic can survive, but what about little indie developers?
What about those poor dockworkers? Any kind of battle with the likes of Apple (or your merchant marine overlord) comes at a price. In some cases people died to fight for their rights. 'little indie developers' are still business owners who will either stand up for their rights or they will have to live with the consequences of not doing so. More likely: those that do stand up for their rights will find themselves kicked out of the App store (monopoly power abuse...) and their competition will thrive.
> 4) An individual developer uniterally striking would be futile and self-destructive. Developers would need to be organized and all strike simultaneously.
Yes, you got it. That's exactly what they should do.
> 5) Strikes are very difficult to organize. Forming a union almost always has to come first. And union members typically work together in the same building, which greatly facilitates organization. Whereas there are a huge number of App Store developers scattered all around the world, and they speak different languages. How would you even communicate with all of them to organize?
I would start with looking for places where App developers congregate and start spreading the message (SO / HN / Reddit / whatever remains of /. / any other forum), write a bunch of press releases and build a movement, then, when the numbers are there for the GADA (the Global Appstore Developer Association) I'd announce the first collective action and take it from there.
It will be work, but so what, if you think it is worth it then it's worth doing well.
As for language barriers and such: there's an app for that...