Can you show me an example of an Expedia or Booking price that is cheaper than a rewards member price from the hotel brand’s official website? A specific major branded hotel, on a specific date, specific room type, where the price is less on OTA versus the official hotel brand website.

Note that it is free to be a member of a hotel rewards programs, and requires giving the hotel brand no additional information, so the rewards member price is the effective price for a hotel brand.