I have one major problem with this advice. This advice is only actionable for people who either already have financial security and can afford to take time off,

I have one major problem with this advice. This advice is only actionable for people who either already have financial security and can afford to take time off, or who don't have day to day responsibilities that demand your spare time, like childcare. If you have all of that spare time, then by all means try to follow that advice. But if you're short on time for life or financial reasons, it's much trickier, and you have to find ways to make many small adjustments to get to a career change.