It would be great if it could become a virtually universal social media eventually, but for its quirks to be understood by everyone, some critical mass of first adopters must understand the fediverse. So I think the fediverse will self-select for technically knowledgeable people at first before eventually becoming accessible to the public, not by any fault of its own but by virtue of having been around long enough and grown enough of a community to attract the average person from traditional social media.
I also think there are different instances and communities for people with different priorities. People interested in the ideas behind the fediverse can congregate on lemmy.ml (because that's where Lemmy's developers are, right?) and in FLOSS communities, etc., while people looking for a social network that won't use them for profit can flock to region-specific instances, etc.