Maybe I am, part of being in a bubble is, that it is hard to properly know that you are. Although I think I prefer the term "to live in ideology" - because it is perfectly possible to consume lots and lots of different, real-life sources, and still delude oneself into believing things, by only viewing them through a distorted lens. But I do see what you mean, and my answer has been: That was also the case when socialist movements first formed, needing to go through a phase of disillusionment with the former French Revolutionary period, as well as Utopian Socialism first developing as a multipronged movement/collection of ideas, until the realities of class struggle shaped it in a specific way. For example: Yet immature phenomena like the Luddites or the Silesian Weaver's Uprising were indeed necessary steps, for further developments later on.
I also cannot say as much about the state of things in the US, outside of internet chatter and mainstream news, that much is true.
I had a talk about this with a friend a few years back, who essentially made the same argument as you did, because all he saw was things getting worse. I think that observation isn't wrong, and will probably remain true for years, probably one or two decades at least. All with political confusion, further vanishing of the middle class and increased barbarism within politics. But it's precisely because things will get so unbearably bad, globally, that I think a material movement opposing it will appear again - successful or not - because that has always happened in history.
Concerning the younger generations: The apathy is precisely a thing, that is also upheld by ideological structures making organisation impossible, by basically making the very thought of being hopeful in any way seem foolish. I don't know if it ultimately will be foolish - but I do know, this sort of pessimistic current has been one of the main ways the status quo defends itself. (See for example Ẑiẑek's famous interpretation of the "coffee without milk/coffee without cream" joke - about how what is presented as not within the status quo is essential to how the status quo presents itself; Similarily with his exploration of how ideology nowadays tends to work by not believing yourself, but deferring to people believing for you - "I myself don't have superstitions, but the others do, so I shouldn't try to exert influence over society that, it would be futile/disrespectful.") Thus, I, of course, don't know how it will pan out either, but I do remain convinced - it's basically impossible to have the total collapse of many essential structures as we, in my opinion, will have/are having, without a dialectically growing answer in the form of a new material movement.
And besides that, younger generations also need some time to escape utopian, childish interpretations, one way or the other - not just in the way movements develop historically, as I mentioned in the first paragraph - but also, how people develop and mature with age.
I get it, especially for users that have always been more on the lurking side (and this isn't judging, that has always been the majority for any platform) - it can be a bit empty. As someone who has been here since 4 years ago (now I'm on a new account on my own instance), the first two years of that basically just visiting every few months out of curiosity, I can slowly see more diverse communities popping up recently, beyond the established strong points of Lemmy (FOSS, Politics, LGBTQ+ memes). And this time, unlike the first Reddit exodus, I have more confidence in them not immediately dying from lack of conviction and activity.
But of course, the sheer gargantuan user count of Reddit comes with many advantages. For many obscure topics, there will still be enough people, that a sufficient amount of "super users" congregate to provide content and moderation, so that lurkers can usually participate and still post sporadically. The latter is of course also a giant advantage, millions of people posting occasionally still provide lots and lots of posts and comments. And of course, it will take a long time and more fuckups for Reddit not simply being "the default" if you want to create a forum for a community around something. (Also, waaay too much of our knowledge is on that platform, we carelessly gave answers to help fellow humans, and now the answers are on Reddit for them to appear in countless internet searches, and for them to do with as they please.)
Where Lemmy currently has its strong suits is enthusiasm of parts of the user base, fewer issues getting noticed at all among the millions of (bot/re)-posts, and where there is activity, I've usually seen it panning out being able to handle actual discussions. (Though, lets not kid ourselves, of course the Reddit-like structure also still encourages circle jerks. I don't even think that is that large of a problem, but it's a reality.)
If you feel you end up having the energy to keep a community alive through dry spell, sure, be the change you seek, but it's okay and understandable if you don't want to invest the energy and work (at the moment). In that case, just stay tuned, check out the communities that pop up in all/scaled or all/new for interesting ones currently getting more traction, the Threadiverse will take a long time before it can replace a giant like reddit, but it has a few good stones for its sling up its sleeve.