Data generated by people isn't random, it has statistical regularities that can be used to narrow down the search space and since quantum computers are better at certain kinds of search problems it will be easier to find fragments of files based on just the hashes of the content.
By getting involved in the government and helping prepare for disasters is the very definition of taking responsibility for yourself and being a resource for those around you.
Then you understand that an individual can not fix these problems on their own which is why I recommended joining folks in your local vicinity that are similarly concerned about these issues and then seeing what can be done at the local level to mitigate them collectively instead of individually.
I think the proper way to prep is not individually but communally. See if your local government has any disaster preparation programs and get involved with those. YouTube videos are mostly for driving ad revenue and selling you garbage after making you anxious and don't solve the underlying problem of fragile global supply chains and supply shocks.
The main thing currently that no one seems concerned about is the reduction of grain production from Russia and Ukraine because of the war. This is going to have a global impact and will increase food scarcity that a 3 month individual supply can not do anything about.
It's unlikely that the US will fall into chaos and political disarray so those are not really the problems people are talking about when they mention increasing income inequality and more polarized politics. And you're right that empires don't really fall in short time frames, it's a more drawn out process but when decaying institutions are combined with shocks to the system like global warming, famines, wars, pandemics, etc. then it becomes much harder to be optimistic about the status quo and the people in charge of managing these shocks.
Things are a lot more fragile and unstable than people realize so it's important to zoom out and look at all these issues in aggregate in order to formulate effective plans for revitalizing decaying democratic institutions so that we can properly deal with the inevitable shocks that cause the decline and collapse of nations.
The main problem is the "mega" part which is mostly a side-effect of seeking profit without wondering whether that's the best way to structure an organization that seeks to "connect everyone" or "organize the world's knowledge". Neither of those missions should be subordinate to profit motives but at the moment the companies that claim it's their mission to "organize the world's knowledge" or to "connect everyone" are actually doing something else entirely: trying to make as much money as possible.
The main issue is that barriers to entry in software are very low. If there is a successful company doing something with software then there is no way to lock someone else out of building a similar service with some slight variation. So I'd say that as long as you are looking at for-profit companies then there is no way to avoid the issue of cutting corners, bad system design, and burning out engineers with stress and overtime because the leaders at these companies know that all the other companies are doing the same thing in order to stay ahead of their competition.
You might have better luck if you start looking at non-profit companies but you'd have to actually figure that out for yourself and work at one to see if it was a better fit for what you are looking for in terms of work.