I think their point is that scaling to the volume of beef production of other countries isn't correct because the methods of production vary widely enough to produce much different results. As in, some countries likely produce more or less CO2/kg of beef so it makes no sense to simply scale the number they got from a single county to global scales.
Not the guy you're replying too though, so I'm not certain.
Now, obviously it would depend on how shit your life is with your parents vs alone, but in my case I was much happier being poor but living with great roommates and experiencing just simple privacy for the first time.