What happens if all countries make import-substituting investments?

The current trend in the United States, Europe and China is to promote investments that will make it possible to produce domestically equipment for renewable energies (batteries, hydrogen, wind turbines, etc.), electronics (semiconductors), medicines and software (artificial intelligence), robots, etc. The general idea is to reshore strategic industries and therefore to make import-substituting investments. We explore what would happen if all countries made investments to replace imports with domestic production: Obviously, the share of global trade in global GDP would fall and the transmission of cycles between countries would be weaker; It is not certain that there would be fewer bottlenecks (as today in the case of semiconductors): why would each country have excess production capacity? As comparative advantages (research effort, availability of skilled labour, etc.) would no longer be used and the lowest production costs would no longer be sought, the prices of the corresponding products would risk rising sharply. So this choice entails more than just benefits (strategic independence, improvement in foreign trade for some countries, skilled job creation).