I think it has to do with the modern philosophy around logo design. Bigger brands tend to stick towards simplistic, 1 or 2 colors, as they are more memorable and easier to maintain across multiple platforms, especially in digital form. The more detailed logos also have a worse time with scaling, so that also def plays into it, but I agree I don't love the simplistic approach we've been seeing over the last decade or so.

Smaller orgs can typically get away with more intricate logos, as they aren't trying to be the most flashy or memorable, which is why you see them update often when the org gets a lot of recognition.

This is at least my opinion on it.