I don't think there's much keeping users outside that demographic away, more so that the fediverse is a tech solution to the reddit problem, so naturally the people that flock to lemmy are the type of person that looks for tech solutions to the problems they experience in daily life.

My mother just had her illegal IPTV streaming box stop working recently, was her solution to find an alternative? No, she simply stopped watching her shows and did other things instead, and complained about it. And that's with full denial of service, not just limited/compromised service like reddit users currently experience.

It wasn't until her tech-savvy nerd son set up another IPTV box for her that she was able to resume consuming the content she wanted to, and similarly lemmy won't really take off until it reaches a critical mass where enough tech-savvy nerds have shown regular people Lemmy as the tech solution to the problem they're facing. What's holding up progress with that at the moment is that the reddit problem for most people isn't significant enough for a regular person to be in a position to do anything about it, even if they are directly inconvenienced.