I know a startup that accepted funding from the valley and stayed in Canada.

Main reasonings: USD goes much further in CAD (longer runway), developers cost less, lower cost of living (most places), and the massive amount of government grants (free money) to subsidize startups in R&D, etc. Federal government just put aside something ridiculous like $900 million for innovation funding.

Last, but not least, Canadian citizenship is a real possibility for someone who moves to Canada under a visa program.