As other commenters mentioned, this has been common practice in app stores for a while now. The integrity and usefulness of any ratings/review system depends on

As other commenters mentioned, this has been common practice in app stores for a while now. The integrity and usefulness of any ratings/review system depends on how well cheating is addressed. None of the reviews platforms have any incentives to address cheating, either because their business model doesn't depend on their reviews functionality (Google Reviews doesn't make Google any money and is unrelated to Google's ad business, so no reason to care about cheaters) or because it's more profitable to take the side of the cheaters and operate a pay-to-play system (where paying customers can moderate/remove/downrank negative reviews) than to operate an honest platform.