First of all, it doesn't make much sense to talk of the "Canadian system." While the federal government does provide some funding and services, most healthcare in Canada is run by the provinces, so quality varies significantly between them.
Secondly, the tax burden is nowhere near 70% in Canada. If you earn over $150000, you might pay 50% of your salary in taxes, but more than that is unheard of. If you have a good accountant and create a corporation you own to funnel your earnings through, and to own your property, you can pay below 20%, depending on the situation (there are many tax breaks for the first 200 000 in revenue a small company generates, you can depreciate your house, car, etc. and use that as an expense, and so forth). An average, middle-class person probably pays 25-35% in taxes.