It's much less practical of a goal in some places. High taxes for example, make it harder to save as much.
It might be harder, but could still be possible. Just because the US has lower taxes, doesn't mean expenses are the same (tons of variables) - just look at our healthcare costs.
I live in the UK and aiming for FIRE
Implying that FIRE participants are only in the US is just as wrong as assuming all developers are in the US.