1) TN is not a real visa. Has to be renewed often and most working long term simply end up on H1B.
2) The US is cracking down on TN abuse too. Just ask tech folks.
3) They heavily scrutinize people who naturalized as Canadians and pursue TN. In fact, a lot of their visa rules look at country of birth, not just citizenship.
On one hand, good on Carney for trying to get more talented immigrants. But given the backlash against immigration, this is equally dangerous. Indeed, I'd argue that a lot of the radicalization in the US against Indians started with all the stories of Indian students in Canada.