Didnt know Qatar scored so high on GDP per hours worked metric, but I guess they dont measure hours worked in construction as that one is largely immigrants working in unsafe conditions with confiscated passports. Source - the book Inside Qatar.
But that's not entirely fair, since Africa to Europe may mean risking your life on a tiny boat, but Mexico to US is at least a land border.
Also UK gets it's share of life risking boats.
I guess Australia was the winner on this, until they took drastic measures to get people to stop risking their lives in tiny boats.
It also quickly becomes meaningless as people risking life and limb tend to flee to the nearest stable country. For example, Syrian refugees for the most part tended to stay close to their home country with the majority fleeing to nearby Turkey, Lebanon, Jordan, and Iraq--or, moving elsewhere within Syria.
Measuring wealth of a country by measuring how many refugees it takes in is like projecting future revenue/success of a convenience store by measuring how many people come into the store during an active-shooter situation.
Going by your metric, it would suggest that a Pole is wealthier than a Brit because Poland has nearly 1 million Ukrainian refugees to the UK's .25 mil.
Also one should keep in mind the danger people subject themselves merely to go the last hop from France to UK.
That's a long way to say that the upstream comment was reading too much into this metric.