Chinese and Indian film studios have been doing this for years on both Rotten Tomatoes and Metacritic. So many absolutely abysmal Chinese and Indian movies have 90%+ user scores on both platforms, it's painfully obvious to anyone even paying a modicum of attention that they're gaming these sites, as there's no way thousands of people can all think these utter turd movies / shows are actually gems regardless of whatever cultural relativism based excuses people try and trot out.
The bottom line is basically every single site that aggregates reviews or has user reviews is functionally useless now, as there are entire multi-billion dollar industries employing tens of thousands of people in China, India, Russia and the Philippines devoted to flooding the sites with fake reviews and the sites themselves know this all to well and do nothing to stop is as they make more money this way.