What was great in the early days of Mastodon is that, for those who could remember, it recaptured the feel of the “early” internet. You could feel distinct and interesting voices, patience and willingness to get into deepdives, where the payoff was from one to one interactions with personalities deeply interested in interaction itself and passion projects.
That made it have a value in and of itself that didn’t depend on competing platforms.
That said, you can feel echoes of typical internet culture all throughout the fediverse now. I don’ think you should measure success or failure on replacing reddit, but its great to have a place ready and waiting to absorb communities that become (say) disenchanted with bad mods.
So the model for replacements I think would be looking at how facebook replaced myspace, and how reddit replaced digg. In both cases, there was widespread user disenchantment at substandard designs and redesigns that disregarded interests of users. I think that kind of catastrophic incompetence and disregard for users was unique to a particular era, and there probably have emerged some industry standards and best practices to stop that from happening in our current internet, for better or for worse.
I think with reddits redesign, it has become increasingly frustrating to the user base, and there is a prospect that user disenchantment with reddit could lead to something, but I think its a long shot. The important thing to remember about reddit is that they caught a wave of exponential growth by not fucking things up, and staying more or less consistent with their product.
I think the best thing Lemmy can do is be consistent and keep doing what it is doing, and not try and reinvent itself. I actually think the website’s functionality on mobile is truly fantastic, the best I’ve experienced from using a website in place of a dedicated app, so I wouldn’t worry about it. I think so much of Lemmy is right in its current for, and 99% of the issue with fediverse products is that the ui/design is being terrible, and it took Mastodon to kind of teach people that it mattered. So yeah, I think the main thing is to not mess with success.