By far the biggest obstacle to me is that the vast majority of Redditor refugees are Ledditors, people addicted to Reddit who are only here because spez took away their third-party app, more Redditor than your average Redditor. This means that ideologically speaking, they are far more likely to be on that pro-NATO Slava Ukraini bullshit than your average Redditor, who's already more on that pro-NATO Slava Ukraini bullshit than your average person walking down the street. Talking to them is basically talking to a wall. There's a slim chance in hell we'll actually meaningfully convert Ledditors.
Besides their greater ideological commitment to the liberal status quo, Ledditors also just want Lemmy to be Reddit 2.0. They are rather explicit in their political project, if you can call it that. They just want Reddit without spez. That's literally the extent of their "vision." They treat instances as backup servers so if one instance's /c/games goes down, they can make the same "Steam sales backlog" joke in another server's /c/games. And since Reddit is fundamentally anti-communist, their Ledditor monoculture will also be anti-communist.
Spez will continue to fuck up, but I don't think he'll fuck up to the point where people who aren't chronically addicted to Reddit will also leave Reddit, with some inevitably migrating to Lemmy. If he takes away old.reddit or RES, sure there will be another Reddit exodus, but it'll just be more Ledditor losers because your average person doesn't know what old.reddit or RES is.
Until the fediverse reaches a point where it can attract people who aren't chronic Redditors with Reddit brainworms, we'll be forever stuck with this cycle of Ledditors filling the fediverse with their Reddit bullshit after spez fucked them over before crawling back to spez after jonesing for updoots.
We are easily the biggest (and arguably only) instance that has formed a distinct culture away from Reddit bullshit, and I don't see that changing anytime soon. (Hexbear's culture is basically some bizarre Reddit/Twitter hybrid with Twitch chat emote spam characteristics.) I don't think any instance could easily form that would simultaneously not be absorbed by us nor be drowned by Ledditors trying to recreate Reddit on their instance. I think to solve the Ledditor problem, we have to be more creative in how and who to outreach. For example, there can effort towards getting /r/thedeprogram or various leftist Discords to create a Lemmy instance.
I guess the fundamental question is we want more socialists on Lemmy, but would onboarding an existing community like /r/thedeprogram or having Hexbear spinoff instances like a veganhexbear count or does it only count when we convert pre-existing liberals into socialists?