The TN visa is arbitrary and random. You are at the whim of an uneducated border officer, who gets to unanimously decide on whether you get to work in the US or not. Furthermore, its renewal is also at the whims of said officer. You better hope he's in a good mood, or you can say goodbye to GoogFaceMicroZon!

Try explaining to them why you have a degree in Electrical Engineering but work as a Data Scientist. My friend tried, and it would be funny if it didn't almost cost him his job. He literally got in due to a shred of mercy caused by his girlfriend's tears at the possibility of a refused visa.

The USA sometimes feels like a dystopian nightmare, mainly populated with idiotic yes-men and ruled by Machiavellian bureaucrats. There are a few niche ecosystems that are impressive, but they are by far the minority.