I think that one of the main goals of lemmy is getting people out of the claws of corporate, cia social media like reddit.
The less people on reddit, the weaker the usa mind control apparatus gets.
However, for this to work, there need to be instances for those kinds of people that are on reddit.
Most of them won't know how federation works and will land on lemmy.ml. If they can't be sent to an instance that fits them, they would probably go back to reddit, or something similar, which would go against that goal.