I worked with a guy who I didn't realize, until reading more about FIRE, whose entire lifestyle (a millionaire who basically used is ex-wife to pay his debts and secretly stored away all of his earnings for years to amass it, all while she thought he was her charity case) is based on these teachings. He even gave me an reading list which he said he came up with, every last one of the books is on all of those FIRE sites.

But, personalities like the Frugalwoods promote their lifestyles as responsible living, based upon a self-made assumption, explicitly selling books and posting VLOGs to teach people how to save money. They omit that they started debt-free & with full savings accounts in the first place.