When you say 'communicate', does that mean posts here will be visible on Lemmy and vice-versa?
Yup! I saw your post from Kbin.
Would you think, then, that Lemmy will have more users than kbin due to the simplicity? Does it even matter?
Yes, Lemmy is the more popular option currently. No, it doesn't really matter that much. Feel free to stick to Lemmy or try https://kbin.social/ , but the content is pretty much the same.