I am not well versed in Android or iPhone software development, but yes, I don't believe that making a non-bloated mobile app is pushing the frontier of software engineering.

There could be some arguments made somewhere as to where R&D money could go, perhaps somewhere in the backbone that billions could use, but the UI is not it.

All that said, I don't know how it furthers your initial argument exactly, as the DMA "beneficiaries" benefit from this lightweightness in zero percent. If anything, it's a negative, because one could assume they have to do better than that with what they're offering.