the US objectively loses a massive amount of foreign policy leverage by not being the largest manufacturer anymore, this is undeniable and obvious when you see how many countries are openly not sticking with the US with regards to Ukraine because they can just side with China, Russia, and India.
The US has gone from 40% of global GDP in the 60s to less than 20%, they've lost relative power when it comes to global issues as a result of that.
The US has also gained immense power through growth in other sectors like finance/banking/insurance - the biggest sector in terms of US GDP. The second biggest sector - professional/business services - also allows the US to project immense power - particularly when combined with the fact that the US dominates global banking and finance.
Looking at a table of US GDP by sector, what rebalancing are you suggesting would increase the ability of US to project power globally? For more Americans and US capital to be involved in manufacturing, some other sector will have to shrink. And manufacturing is already the fourth biggest sector.
The US has gone from 40% of global GDP in the 60s to less than 20%, they've lost relative power when it comes to global issues as a result of that.