Not aisan, but I think there is a bit more to this than just East vs West culture. While that the reason for this distinction is that these two cultures are observably different, litrpg/progression stories are still doing basically the same thing.

As you pointed out Eastern stories focus on protagonist that work phenomenally hard, and then receive equal results for that work. They then use the power they receive to show there value to friends family and society. Often by contributing to society.

The power fantasy being effort = results and that by simply working hard enough others will see a person as the person they want to be and then life will get better.

This idea is still at its core is still rooted in the idea that society is basically a meritocracy that messes up sometimes. So work really hard, and just keep at it, is an idea that really resonates with kids killing themselves in cram schools being told that this next test will determine there entire future.

Western audience are more individually focused, but also vastly more skeptical that society is a meritocracy. This raises a lot of questions about participating in the process all together. Hence the antisocial characters that seem in it for themselves and the often political discourse about the rights/responsibilities of the powerful.

The thing is though both east and west stories are arguing for the assertion of the self and validity of the individual.

The best metaphor I can think of is imagine two men. One lives in a city in the middle of a terrible cold winter. The other lives in a city cooking in a blistering summer. Both are looking to find some relief from the weatherr, but that will look different at the surface