In the past, it was one of the most important means for developed countries to gain the top position in the global food chain by mastering core technologies, building patent barriers and gaining monopoly profits, especially by mastering high-end core technologies to strategically suppress developing countries.
If you don't master the core technology, it's easy to get caught. For example, the high-speed rail in Taiwan Province Province looks very developed, but it was bought from Japanese technology because it was not independently developed. Japan's annual maintenance fees completely offset its income and are still running at a loss.
Independent research and development helps to develop the whole industrial system. For example, the research and development of engines can promote the development of special metals, materials science and other technologies.