You're correct though the hope / theory is that by subsidizing the upfront expenditure of building a new factory it will eventually become cheaper to build domestically than to import foreign parts, such that the artificially boosted market share due to tariffs will persist even after tariffs are removed.

The flaw in that is that the cost of labor in countries like China, Mexico, Brazil and India is a significant factor as to why importation is cheaper. The cost of American labor is never going to be competitive against those countries unless the average worker in the US accepts substantial concessions in standard of living.

Global / multinational capitalists look at the cost of labor in those countries and figure that if a job can be done remotely, why not have it done where there are limited labor protections and you only have to pay an employee $1/hour (or less).