Why is reddit so popular?

Great anonymity

You can view any post whether you have an account or not, and whether you follow a particular topic or not. Only when you want to publish, do you need to register for an account, which does not have to reveal any personal information about you except for your username and email address.

Focus on topicality

Reddit is a big community, composed of many topics. Users can easily interact with strangers from all over the world about common interests. You can add your topics of interest to the system. The content displayed on the homepage is based on topics, rather than those published by the accounts you follow. In this way, you can focus more on the comments of every ordinary user in each topic—everyone is equal, instead of some unexciting content posted by some accounts with many followers.

Be content-driven

Reddit uses the Karma system. Karma is calculated by subtracting the total downvotes an account has received in its posts and comments from the total upvotes for an account. It is a much fairer way to determine how much a user contribute to subreddits on the platform.