Lemmy is a federated social network, similar to Mastodon, where anyone can create and run their own instance. This means it’s not centrally controlled by one entity. The reasons for having many instances include:

1. Decentralization: This reduces the power of any single entity over the entire network and prevents any central point of failure. If one instance goes down, others are unaffected. This design also helps resist censorship because content moderation is handled individually by each instance.

2. Community autonomy: Each instance can form its own unique community with its own rules and norms. This can promote diversity of thought and freedom of expression, as different communities can have different standards and policies.

3. Privacy and security: Having separate instances can provide a higher degree of privacy and security. The admin of an instance only has access to data from their instance, not the entire network.

Regarding the concern of popular instances becoming like Reddit, it’s worth noting that decentralization inherently provides a counterbalance. If an instance becomes too dominant or its policies become unpopular, users can migrate to or create a new instance. In the end, the federated nature of Lemmy allows for a much more democratic and user-driven online community.