Speaking solely wrt Lemmy, I think what's going to happen is we won't get the "brand recognition" of the technology like what Reddit has had. But, we'll probably see instances get closer to that sort of broader familiarity. So someone might not exactly identify as a lemmy user, but maybe as a Beehaw user.
Anecdotally, I had to try a couple of times to fully "get in" to a Lemmy instance because I didn't know that the hell I was doing. I had tried using gerboa as my client but couldn't understand why I couldn't log in or register on an instance. Then I tried again using liftoff, and it kind of clicked more easily.
Maybe email felt like this in the early 00's? I knew what I could do with an email address (e.g. sign up for MSN and AIM), but I had no idea how to get an email address until I had my siblings walk me through it. I think if any instance can pull off a killer onboarding experience, they'll become the Bandaid, Jello, Kleenex, etc of Lemmy.