[adventured]

The solution to that is to strip out the profit, Wikimedia style.

Building review sites is the easy part of it, that isn't preventing anything due to competition (like a programmer creating blog software to compete with Wordpress, building it is the easiest part; or creating an online store / shopping cart service to compete with Shopify). Building it does nothing of consequence. Acquiring hundreds of thousands of high quality product reviews is extraordinarily difficult, and then you have to keep them coming in forever at that high quality.

That these things are easy to build at a basic level, poses absolutely zero challenge to Wordpress or Shopify et al. I'm not exaggerating, it threatens them not in the least, because it's meaningless. It doesn't matter if someone can build an Uber clone in N months, they won't be able to do the actual hard part of competing with Uber.