Bringing up user experience when talking about branch predictors is meaningless. Just as bringing up branch predictors when talking about perceived performance. (unless you're proving that this exact feature being available/not available, with other things being controlled for, makes a major difference in the test)
If working on branch predictors does not impact the user experience, then arguably that work is meaningless in the context of building real products -- it may still be interesting for academic purposes.
But, for the final user, it doesn't matter if each technology alone is better than another. If you have a background 64-core processor, driven by another 8-core... What matters is how fast something loads, performs, and how long batteries last.
Of course, this might be outplaced in a thread discussing NN branch prediction.
I would argue that would be a completely useless test unless you're explicitly testing something for development purposes only. Users use phones. Nothing else matters but the user experience. If you can make your phone beat another phone in your limited, no disruptions, network traffic off example that doesn't mean anything.
I feel this is a fair test. You test the phones at what they're supposed to be able to do. If one does it better it's legit to point that out regardless of what the underlying structure looks like.