The problem is that the masses seem unlikely to enjoy the bulk and complexity that comes with such an infinitely modular phone, and they definitely won't enjoy

The problem is that the masses seem unlikely to enjoy the bulk and complexity that comes with such an infinitely modular phone, and they definitely won't enjoy the higher cost. I think people sort of have this idea in their heads that manufacturers can easily make something just as cheap and usable while lasting forever and they just don't for profit reasons. But I see very little evidence that's actually the case and applying some critical thinking and engineering experience suggests Apple is probably not just holding out on us having the infinitely upgradeable iPhone of our dreams. Again I'm sure they could make one, but they realize the market is small especially at the likely price point and given other tradeoffs they'd have to make.