Consumers would have to choose a different device if, say, Apple saved money by putting in a lousy screen or a cellular radio that was unreliable... What transitions these ecosystem misfeatures to anti-consumer in a way that an inferior screen isn't?

(I submit they aren't anti-consumer; they're ecosystem control and some consumers find that to be a feature. I know I feel safer recommending my grandma an iPhone because scammers won't trick her into side-loading a root kit into it or loading some fake banking app that she pays money into that just disappears).