Korea and Japan are two different things. and there products especially the high ends are looked very differently.
Samsung even today has major Research centers in Europe and Russia.
Korea will have to pay much more to keep those relationships.
Japan approach is much more domestic.
KHI, MHI, Toray are much bigger suppliers to Civilian aerospace. where quality and reliability are paramount.
These people have tested on mass scale and they know difference in reliability when dealing with desert heat.
I'm fairly certain there are plenty of Spanish, Chinese, Italian, Indian, UK, Russian etc suppliers to civilian aerospace of just Boeing, Airbus, Embraer, and Bombardier (countries not USA, France, Brazil, and Canada is the point).
Japan isn't unique in supplying civilian aviation. So many suppliers in various countries have been doing this for the main duopoly for years if not decades.
Desert testing of cars is universally standard practice. Even 1980s Chinese cars did desert testing. Nowadays many have giant autoclaves and testing facilities that can simulate conditions far better than deserts, poles, and dust storms etc.
Samsung and Hyundai are South Korea's two crown jewels like TSMC is for Taiwan or Sumitomo for Japan, Huawei, CATL, BYD, SMIC, SMEE etc are for China and so on. Koreans paying to keep those relationships is a weird thing to say. Those research centres are a source of "biodiversity" so to speak. It creates resilience and can improve Samsung.
Japan keeping a domestic approach isn't necessarily only good. They clearly miss out on things. Microsoft had offices in China (might still do) and so on. They take advantage of the talent and people in a country. That's what some of these multinationals do. There are American engineers working for Dutch Philips corp inside the USA in facilities owned by Philips where profits go into the Netherlands and shareholders when they create some new product. The work and gain given by those American engineers working at Philips, contribute to Philips the company and Netherlands the country (to some degree). It isn't a bad thing to have foreign offices and using foreign talent. In fact it is downright stupid to refuse that option as some weird self imposed rule.