> All of which are detrimental to Apple because they force apps to adopt a lowest common denominator approach and not use the latest Apple technologies.
I think you might have this backwards. What you say used to be true back in the days of phonegap, where the hardware was abstracted far away, but all of the frameworks you mention provide pretty easy paths to access new APIs and hardware features. But companies that are drawn to cross-platform tooling already want a uniform experience across devices - and that's why you get the lowest common denominator being used with tools like react native.