IMO, fire becomes impossible the second you have kids. Because all parents I know have some kind of super natural urge to provide better for their children. A house in a better school district, university education and the knowledge that they can have more if they work more, will inevitably stop people from making that early exit they so yearn for.
This becomes even more evident once you get used to roaming in 'high achieving' circles, because the second you RE, you and your children get pushed to the bottom of that social structure (in terms of material possessions)
FIRE also has a wierd hypocrisy to it. It advocates for avoiding life style creep. But, if you avoid lifestyle creep then you can pursue any of the things you would have after retirement as a primary source of income anyways. Especially if you don't expect to take on fresh debt. (new house, new car etc)
That being said, I live a FIRE esque lifestyle too. Because the core tenents make sense even without wanting to FIRE. But, every tech guy in their 20s seems to want to Fire, but I haven't met a single person in their 40s that actually has.
The more the press talks about it, the more unusual it is. See shark attacks vs automobile fatalities.