I honestly think every single platform that uses a vote score system is inherently vulnerable to becoming an echo chamber.

The only value a vote score generates is consensus. This is at the cost of influencing readers before they even engage the content. It lowers the bar of participation, partly by removing the necessity of commenting approval/disapproval, and secondarily by making approval/disapproval anonymous.

Ultimately it makes it easier for people to participate without actually contributing and that lowers the quality of the end result.