Horses for courses.
It's way more reliable for capturing a small static bird in mid-ground. That's important to shooters wanting record and environmental shots. It produces a higher rate of sharp shots in BIF bursts but the Sony does enough. The Sony is easier to use grabbing a BIF against a plain background and not much different against a textured background.
Other pro cameras use cross-type PD sensors. I wonder how much Sony's AF would improve if it did.