Why does the reason matter? If Cisco isn’t competitive, they die. How do you propose they stay in business when Huawei is selling the same thing for half the price?
Alternatively, the USA as a country could put some effort into education, so as to be self-sufficient in available, skilled workers.
But you're simplifying things - do we really know that lack of cheap Indian H1-B or L1 workers is what's killing Cisco? No. We don't even know that Cisco is being killed. They just gave $10+million dollar bonus to the CEO, as we learned elsewhere in these threads. That suggests robust health.