The US has had to share its scientific leadership for some time already, and China is now seriously challenging its technological leadership. It continues to attract foreign academic talent, mostly because its academic salaries are less competitive against industry salaries than in other developed countries. Because Americans are less likely to pursue academic careers, it's often easier for foreign academics to find opportunities in the US than in other countries.

Who was responsible for CRISPR is good question (I'm less familiar with the advances leading to LLMs). There was a series of incremental advances building on each other from at least Japan, Netherlands, Spain, Germany, the US, France, Sweden, and Lithuania. And the Nobel prize was shared between an American researcher working in the US and a French researcher working in Sweden (and later in Germany).