Don't buy their devices. Apple is not a government that can coerce you into submission.
I know it's not the same scale, and i'm not trying to compare poverty and human suffering to a web browser, but IMO there are some similarities.
Switching to an entire other OS which many believe to be less secure, that in many cases doesn't have many of the same applications, and significant changes to everything you do on your device (which for many is their ONLY device connected to the internet), for a web browser?
People won't do it, and I (as a web developer) don't think they should give up everything for a few web features. But when one party is purposely holding the ecosystem back, something should be done. They need to improve, or open up the playing field to others that will improve.
IMO forcing "operating systems" to be more inclusive would be a good thing, and could really improve not only iOS, but Android and Windows as well.
I don't know how this would look legally, i'm pretty far from a lawyer, but the discussion is at the very least worth having without hand waving any complaints away with "just buy an android"
Apple has a monopoly on iOS devices. There is no competition. And if somebody would built a better or freer iOS device, Apple would use the full force of the state to stop them. So, in a very narrow fashion, Apple does use their government-granted rights to coerce you to buy it's devices, if you want an iOS one.
Of course, nowadays Android devices are more than adequate replacements for many users, so most people do have the option to buy outside of the Apple world, as you suggest.
And if you were complaining as a developer, that wants to distribute your software around, you'd have a point.
But the GP is complaining as a user, that has complete freedom to choose the phone he is buying. He just want the shinning locked-up one, but don't want the consequences of the locking-up. He has all the right in the world to complain about it, but if he won't do anything about it, why would anybody care to listen?
But no one can sell me e.g. an iPhone 7 with audio jack. And I can't build one on my own.
Sure we can! Vote with your wallet and don't buy Apple's products. Or at least write a complaint to one of their support centers..
There's a saying; "What you don't know can't hurt you", and that can be applied for these users - whom make up the majority of iOS device users - since they don't know what they're missing out on. While you and me on the other hand knows what we're missing out on, both as programmers and users, we at least have the chance to vote with our wallets. I do, perhaps even you do, but as you can clearly see it's still not enough to even make a dent in Apple iOS device sales.
But to my opinion, everyone here knows Apple is blocking HTML 5 somewhat and there is almost nothing we can do about it.
PS. General public/buyers don't know and i already changed from iOS, because "add to homescreen" doesn't work as well as on Android