Which country is the worst at Chess?

Any such discussion - like those of "the best" suffers from lack of definitions and therefore of metrics. What does one mean by "the worst"?

It doesn't need any definitions.

When a group of people who play chess, say a chess tournament, finish the competition there is usually someone who is in last place. That person (or persons if there is a tie) is considered "the worst" within that group.

So "the best" is going to be a country that has players who have high ratings, do well in tournaments, etc. Countries that might be considered "the worst" would probably be ones with low rated players (or possibly no rated players), players who finish poorly in tournaments, etc.

The only exception I can think of is a small, isolated country with a substantial prison population. Prison inmates always seem to be good at chess.

One always needs definitions - you've presented a number of different metrics there, and different countries could potentially be last according to which ones you use. British Virgin Islands finished "last" in most recent Chess Olympiad, but at least they sent representatives so maybe it's fairer to say they finished 188th, and the other countries who didn't send anyone are "worse" https://www.chess.com/events/2024-fide-chess-olympiad-open/results

What if there was a player from one of those countries higher rated than anyone in the British Virgin Islands but just couldn't go last time? That was mentioned earlier.

Flip it to the opposite: what country is "best" at chess? That is impossible to answer without choosing one or more ways to measure it ie. to define what you mean.

Norway could be at the bottom. They only have 6 players above 2500 other than Carlsen. https://ratings.fide.com/rankings.phtml?country=NOR

China，nobody knew Ding‘s win in 2023 except player

I'm guessing Japan but we can't really know

It could be one of those small independent countries

British Virgin Islands are listed at the bottom of this standings list with at least some points. Not sure how the rest below them were involved. But they all had 0.

https://chessolympiad2024.fide.com/open/standings

The only way to accomplish that is to not post anything. This is 2024. It's very fashionable to feel insulted.