Seattle has a much healthier market both for devs and real estate and is only three hours away.
Only difference in healthcare is while american top devs get it on top of their compensation packages, canadians pay for it with their prohibitive income tax rates. It's pretty easy to take the total spending percentage that goes to healthcare and multiply it by your income tax to see how much a dev is really paying for healthcare.
I'm also not quite sure what you mean with your point about healthcare. MSP premiums were eliminated last year [0], there is now no charge to access medical care. Prescriptions, dental and eye care are all still chargeable, though prescriptions at least are essentially capped through BC Fair Pharmacare [1].
Compared to the US, Canada is much easier for immigration as a tech worker. One can get PR (equivalent of a green card) before landing if they have a sufficient points score, in BC that's fairly easy through the tech PNP [2] and a willing employer.
Additionally Vancouver consistently ranks among the top 10 most liveable cities [3].
[0] - https://www2.gov.bc.ca/gov/content/health/health-drug-covera...
[1] - https://www2.gov.bc.ca/gov/content/health/health-drug-covera...
[2] - https://www.welcomebc.ca/Immigrate-to-B-C/B-C-Provincial-Nom...
[3] - https://en.wikipedia.org/wiki/Global_Liveability_Ranking
I'd argue that if you got a CS degree from an American college you're probably just forced to work in the US simply because the other prospective employees can accept a lower salary due to a lower debt load. Maybe the best of the best can find a way to earn American salaries overseas but I really don't think that's as common as the HN crowd might assume.