This kind of list crops up pretty often, but again the implicit implication doesn't hold. These products are not "top" because they have good pricing pages, they have good pricing pages because they're at the top. I remember most of their pricing pages on their way to the top of their respective fields, and they were shitty.
The point of a list like this isn't to say this is what these companies did when they were small, it is to say this is what they are doing as best practices now.
The other way to look at it is that they have good pricing pages because at scale the ROI of optimizing certain user journeys is gigantic.