I agree that a truly solid package system, is inherently a good thing for any framework. But it has to be just that. Qt is severely lacking in that aspect; qpm isn't even close IMO.
Counter to your point though, just take a look at the ecosystem around NPM for instance. What a mess...
For a cross platform development framework, to truly shine, I need to be able to "trust", that my majority use case is covered within the framework itself, so I don't have to go package shopping and spend a lot of time on quality controlling vendored code.
For a mobile app framework, I want the most ubiquitous device capabilities covered. That means various hardware specific things, such as networking, gps, bluetooth and yes, the camera. Whatever is to be expected present on most devices.
So yeah, I guess it boils down to dependability and trust. Something which is implicit in the framework and core library for the most part.