I can agree with this. As a general statement, it’s mostly correct. But it’s not a blanket rule by any means. Areas where I’ve lived in my life, Bing actually has higher quality and more recent data than Google, surprisingly enough. Granted, I’ve lived in either remote or rural regions, and my current city isn’t exactly a major metropolis.
However, there’s a caveat here. In most major urban centres and their surrounding regions in North America and Western Europe, Google’s data is generally higher resolution. Maybe or maybe not more recent. Generally speaking, Google data is better. But like you said, this is nowhere as clear-cut as that.
Google definitely has more photogrammetry coverage, and for the most part, it’s of higher quality.