How do we deal with similar communities on different Lemmy instances?

Say what you will about reddit, at least an established subreddit was the place to gather on the topic, ie r/technology etc.

With Lemmy, doesn't it follow that similar communities on different instances will simply dilute the userbase, for example [email protected] and [email protected]. How do we best use lemmy as a (small c) community when a topic can be split amongst many (large C) Communities?

This is an earnest question, in no way am I suggesting lemmy is inferior to reddit. I'm quite enjoying myself here.