The difference between New York (the highest US state by per capita GDP, ~$91,000) and Ireland is larger than the difference between Mississippi and a per-capita GDP of literally zero.
Also, I forgot, it's a disingenuous comparison if you know anything about how life, subsistence, marginal savings rate & co work, which I assume you do if we're discussing these kinds of topics.
The scale of "GDP per capita and how people are living" is roughly this:
At a "GDP of literally zero" you're DEAD.
At a GDP of 1k, you can afford a cheap bicycle.
At a GDP of 10k, you can afford small, old, beat up and unsafe cars.
At a GDP of 30k, you can afford almost all modern amenities, they'll just be smaller, older, have fewer features.
At a GDP of 80k you can do whatever the hell you want if real estate expenses aren't killing you.
So no, you can't freely compare a country at 10k with one at 80k and try to bail out the comparison with PPP.
And the difference between 1 billion and 1 billion 30k is 1 billion. Percentages matter, thresholds matter. The person having 1 billion 30k doesn't have a materially different life to the person having 1 billion. The person having 30k is reasonably well off, the person having 0 is dead. The person having 40k is also reasonably well off while the person having 10k is poor (and NOT US poor, world standards poor; which BTW, is about the global average, which makes the average person in the world poor by modern development standards).
It's an average. You can average zero in with 140 and still have a higher average than the average of 90 and 40. And what do you expect if you don't average in the zero?
GDP per capita, PPP[0]:
[0] https://en.wikipedia.org/wiki/List_of_sovereign_states_in_Eu...The difference between New York (the highest US state by per capita GDP, ~$91,000) and Ireland is larger than the difference between Mississippi and a per-capita GDP of literally zero.