Anyone can create and administer vs. Reddit’s centralized control. Whether this is an advantage or not depends on your values. Many people have moved to Lemmy from Reddit recently because the folks that run Reddit have made some unpopular decisions and, because Reddit is centralized and closed-source, the only options are to accept the admins decrees or abandon the platform. On the other hand, if the administrators of a Lemmy instance make unpopular decisions, it is easy to move to another instance or create a new instance with different administration.
It seems you have it in your head that it is correct for Lemmy to “try” (whatever that means for an open source project and a decentralized federation of instances) to replace Reddit. That is not, however, what Lemmy is “trying” to do. No one is making you stay. If you like Reddit, like I said, go on back. I, for one, will be staying here.