Iphone doesn't let you search photos really - try searching for "photos of me skiing" or "igloo picture" and you'll soon find google photos is way ahead.

I just tried "igloo" in photos and it immediately showed the only picture of a snow fortress that I built with my kids 7 years ago. "skiing" also worked fine, as expected, but "Tom skiing" did not.

Since the first level implementation works fine, you're talking about a second level detail. Do you think this would nudge enough people towards using Google Photo to actually matter?

I very much doubt it.