How could anyone tuned into Google be surprised about this? Pichai's Google has barely managed to make a consumer facing product/SaaS that wasn't inevitably killed off, barely worked at all, or competing with a parallel Google product at the same time. Their latest woes with AI and internal culture clashes are just the latest bubble rising to the surface of what's been going on internally for a very long time.
I expect Pichai will be replaced by Hassabis in less than a year.