On one hand, yes, I agree: duplicating the full functionality of a website for the sake of having an app is far from being ideal.

On the other hand, I also believe that this 200 MB comes mainly from 2 sources: bad engineering from the application developer, and bad engineering from the platform developer. These are not toolkit dependent, however. Bad engineering will create bad products, regardless of the tools used, even when some tools are harder to misuse to create bad products.