Political upheaval and social instability are definitely not desirable and may make reaching FI difficult, or possibly impossible. We can only change course if we let go of excessive consumption of energy. From an anti-fragility point of view, a few shocks would be great and make resilience more mainstream concern, but a collapse of ecosystems and economies is very bad for early retirement prospects. Expect to be either starving or subsistence farming for the rest of your life, unless of course you position yourself somehow to be lord of the manor at the expense of those around you.
Humans are pretty adaptable, for the most part, although most are forced to change only once they are pushed over the metaphorical cliff, rather than take the initiative. The ERE folk here are the few who would likely take the jump before they are pushed. Once the rest of the population start to notice the benefits of jumping, under the right conditions, a few might be tempted to follow, but most won't. I think jacob did a blog post where he said that 20% are capable of learning and taking proactive action, and 20% of that 20% (4%) are capable of showing others the way. The timing however is crucial for most of the population, the changes will only happen once the current way of life has demonstrably failed, i.e lost everything in a recession and sea front home is about to fall into the sea.
I guess it makes sense that on aggregate, humans don't all change so easily, less an otherwise sustainable society might inadvertently change course towards unsustainable courses of action because a few kooky pioneers found a 'better' way of doing things. Collectively as a species we are hard wired to make the best of what we have, until we can't and move on to the next best thing. As with overeating, it takes extreme discipline not to over-consume, and most just don't have it. The only way they will change, is to get used to it there being a lot less stuff around to consume.
At least we as a (ERE type) group can see it coming and can best position ourselves for the storm.
Collapse now, and avoid the rush comes to mind.