> because photos don't require highest speed cards

That hypothesis is certainly getting tested these days in specific niches. With high megapixel sensors, pre-capture, and cameras capable of pushing between 30fps and 120fps worth of compressed raws or high quality JPEGs, you can obliterate your camera's write buffer and CFExpress write bandwidth. You can make many bad photos of an animal, bird, or athlete with extreme ease -- and hopefully find that one winner in the haystack.

I would say the line between movies and photos is getting blurred, but it's unlikely you're using a shutter speed that allows for motion blur with these bursts of photos!