They should not conflate all of Asia with East Asia/Confucian societies. North Korea, as an hermit, isolated regime, continues to underperform.
The only schoolchildren who outperform Western schoolchildren on rigid tests are East Asian, maybe partly, due to their rigid schooling systems. Japan and other developed Asian countries are beginning to shed their dogmatic, rigid approach to adopt a more flexible one. That's why you are beginnng to see those democratic East Asian countries slip up in these rankings in recent years.
You obviously don't have any clue about the nature of PISA tests. You should google. This is why China's performance first time it joined was so shocking that OECD held up the results for one whole year so they can find out where they went wrong in the statistical sampling. They couldn't. Every prejudice and stereotype from sampling methodology to all possible ways to game the system to migrant kids during harvesting period were hashed and rehashed countless times in the last ten years. In the end, the conclusions stood and China repeated its domination with expanded coverage in 2018. Britain even had a reality TV show with Shanghai teachers in UK.
The clustering of the top PISA scoring countries have not changed at all. All East Asian plus a couple Northern European. Nothing to do with 'democracy' or any religion. You sound very close-minded and judgmental. You would not have done well in PISA. There is a ton of academic analysis on PISA/China as even kids in the remotest and poorest regions like Guizhou in China outperformed avaerge OECD countries. The simplest and most straightforward explanation is East Asians are smarter than Western Europeans and don't expect the Indians to be able to catch up in the next few decades.
PISA is all about deductive reasoning, logical thinking, and comprehension. That is why it is such a amazing proxy for IQ tests.
Here is a link to a fascinating analysis of various countries' super genius pool after the 2018 PISA round. 2021 PISA is postponed until Fall 2022 so we'll find out the latest results (including India) in 2023. Obviously India talks big about their chances to move up (not hard as they were second from bottom) but they probably will be disappointed and quit again.